Seattle Center, which has been trying to come up with a master plan for future development for the past four years, has now unveiled its most ambitious blueprint yet. It's called the Century 21 Master Plan, using a phrase that evokes the 1962 World's Fair. The plan now goes to a series of public hearings and then a vetting by the City Council. First soundings from the council: The plan is not quite ready for prime time.

It's no easy task to produce a coherent plan. The earlier effort, in 2004-05, was stillborn both because it was pretty much just a wish list of powerful tenants at the Center and because Center Director Virginia Anderson was on her way out of that position, and a lame duck at City Hall. The Seattle Center folks regrouped, formed a committee with a few outside-the-Center perspectives, and decided to think a bit more boldly.

Both plans concentrate on "the center of the Center," meaning the neglected heart of the old fairgrounds: the rundown Fun Forest, the funky Center House (an old armory), and the lightly used Memorial Stadium. The 2005 plan was going to replace the Fun Forest with more free attractions and updated things for kids to do, and blow out some walls of Center House and make it a kind of atrium with a big glass roof. Those ideas survive in the 2008 master plan.

What the new plan adds is a proposal (only that, so far) for knocking down Memorial Stadium (firmly guarded by the Seattle School District and veterans' groups). In its place is an awkward compromise. The current stadium bowl would be used for underground parking, with a large lawn on top. East of that would be a new playing field for use by school teams in spring and fall, with a grandstand on the east side that turns into a stagehouse for summer concerts. One drawback of this scheme, which is meant to appease the School District and festival promoters such as Summer Nights/One Reel, is that it presents the blank backside of the grandstand to Fifth Avenue and the new Gates Foundation offices. Not exactly the best way to create a lively streetscape.

Still, the proposal does greatly extend green open space eastward from the large International Fountain and should work pretty well in the summer, when the football field is replaced by a green cover. August Wilson Way is laid out as an east-west walkway just to the south of theater row. (The theaters nixed the idea of a slow-moving streetcar along that route.) There are some attractive-looking sketches of landscaping and botanical displays in the area behind the Horiuchi Mural and west of the Space Needle (now a bleak kind of tourist zone). One nice touch in the play area to replace the Fun Forest is a wading pool that turns into an ice skating rink in winter. Higher quality restaurants are introduced, including one on the roof of Center House, and more retail, office space, and community meeting places are put over near Lower Queen Anne (much depending on KeyArena's future). Total cost is put at $676 million, but the figure is a stab in the dark, not counting private participation and commercialization opportunities.

Don't mistake me for a neutral observer. I was part of a group advocating for a bolder central idea for the Center, turning the interior 30-40 acres into an urban parkland. The key to this, in our group's view, was demolition of Center House, which sits awkwardly in the center of the grounds and whose massive concrete walls block any visual sense of a large, contiguous park. We proposed "editing" Seattle Center to remove some old buildings and uses, giving a clear dominant image and finding a way to give downtown Seattle (starved of parkland) a signature park.

The Century 21 folks took a good look at removing, or moving one block south, Center House, and also designing some new spaces to accommodate uses like Book-It Theater, the Children's Museum, and Center School. Instead, the committee decided to try, one more time, to make the ugly old armory into an attraction, meant to pull people into the heart of the Center. The central atrium will have a performance space, stairstepping down to the lower level like the ungainly Microsoft Auditorium at the Central Library. The east and west walls will have cafes that face inward and out to the grounds, and the south wall will be replaced with glass hangar-like doors that can be flung open in good weather. A bubbleator is revived, carrying people up to rooftop viewing and the destination restaurant. (If you are feeling a sense of straining too hard, so am I.)

If your goal is to rationalize the current users of the Center, to create more opportunities for revenue (and corporate underwriting), and to make the hodge podge of uses work better together by using the green space as a connective tissue, the plan works pretty well. It makes a few more connections to the surrounding neighborhood, but not much. The new parking garage at Memorial Stadium has all kinds of advantages, especially in allowing underground loading from trucks and buses, and it might even become a transit center (Metro buses, a streetcar, and the Monorail), as proposed by King County Executive Ron Sims. The big open lawn will work better for large festivals. And the overall plan, jumbled as it is, retains the populist, pluralist spirit of Seattle Center.

That pluralist spirit also pervades the planning, which combines many architectural firms rather than having one master planner or envisioning an international competition to pick such a firm. The main architecture firm appears to be SRG Partnership, a Portland firm with a Seattle office and best known for laboratory and health-services buildings. The Seattle principals, led by Dennis Forsyth, used to work at NBBJ and were involved with the previous upgrade of KeyArena.

The plan certainly seems to be driven by the needs of multiple (often very powerful) clients, rather than by a powerful architectural vision. The clear example of the latter would be the Olympic Sculpture Park that SAM opened last year, reflecting the striking vision of Weiss/Manfredi Architects.

Given all the entrenched constituencies at Seattle Center, and Mayor Greg Nickels' aversion to headstrong architects and Paul Schell-like "vision things," it's quite unlikely that the Center would settle on a strong, central theme, particularly one that would involve moving the furniture around. After all, mayor after mayor since Gordon Clinton in the 1960s has tried to pry Memorial Stadium out of the hands of the School District, which holds the lease. And when the Disney Imagineers presented a bold scheme at the end of the Royer administration, they (and nearly the mayor) were ridden out of town.

You could make the case that the city has changed, that the new and more sophisticated population here now really likes bold statements like the Rem Koolhaas Central Library. There won't be many voices in that camp at the City Council, which has been mostly concerned about costs and the annual subsidy of Seattle Center. But as the city enters into one of its favorite topics of debate, one perilously close to those iconic, "soul"-of-the-city wrangles, we will see if those new voices actually clear their throats and speak.