Honestly, I really don't see the problem here. I very much agree with Expo_Seeker40. It's not like there haven't been large bulky stages in this very location in the past. Take a look at this pic from December 2002:
The stage in this pic was
enormous compared to the new 2009 stage. And as far as theming goes, it had some metal features in the front and green triangles on the side. That's about it. Otherwise, it was a huge, obtrusive, bland structure with exposed skeketal features throughout. I'd say what we now have is a lot more interesting and thematically appropriate for Tomorrowland.
Also, I think that the final "Stitch" stage, in actuality, is a lot better than it's proposed artist concept (seen below). I think that the shades of silver, purple and green that we received make a lot more sense than the orange, gold, and copper in the concept. That color pallete was more DL NewTomorrowland circa 1998.
From an architectural standpoint, there are a few features of this new stage that reflect structures seen elsewhere in Tomorrowland. (See below) The curved roof seen here reminds me of the angled roofs along the Northern side of "Avenue of the Planets". The two curving silver spikes seen on the sides are extremely similar to the legs of the TTA (evident in my next picture below). Even the stage's small details like the circle motifs and orb-like door covering are TL staples.
Furthermore, I am a huge fan of the "video-billboards" or advertisements on the monitor. With references to 9-Eye, The Timekeeper, Tom Morrow, the Tomorrowland Metro Retro Historical Society, and the cohabitation of humans, aliens, and robots, this only furthers the expansive backstory and layering of TL. It's very similar to the ads you already see all around the land, and hear on the TTA. Yes, they are corny and loaded with puns and obscure references, but so are all the other ones that have been around since the '94 land refurb. These videos especially remind me of the TL phonebooth near the Astro Orbiter with it's cheesy humor. And without a doubt, the news broadcast is a decendant of the 1994 Space Mountain queue TV program known as "SMTV". Anyone remember that? Check out all these videos of the new "TNN" as seen on the stage and you'll see why I'm such a big fan:
http://jefflangedvd.com/2009/04/first-glimpse-stitchs-supersonic-celebration-construction-walls-down-in-tomorrowland-today-photos-exclusive-video/
I applaud all this plussing to the TL story and I'm surprised that so many of you are disappointed with these additions. I think the only things I
don't like are: 1) the pointed, boxy back end of the stage and 2) the fact that it has to be a show about Stitch.