I can't find any other source for this, but the blog Home Run Derby is reporting that the Royals and Blue Jays are returning to their powder blue uniforms in 2008. Alternate homes, it seems, as opposed to regular roads, and the Royals only from the waist-up, but they'll be on display all the same.
I hope this is true. While powder blues were an abomination on most teams, I always thought they looked natural on the Royals. This is due in most part to George Brett, I suppose, who I had the good fortune to see kill the Tigers in his roadies on numerous occasions as a kid. If you do something as well as he did, it doesn't matter what color you're wearing. You're going to look good regardless.
Cubs, Cardinals, Phillies, Braves, Rangers: don't even think about it.