It is definitely difficult enough to cull out a huge segment of potential developers. The only online store that you might be able to make the case for being pretty open is XBLIG (or whatever it is called) which is still pretty limited in terms of what you can charge or do with the game system.
I think a good standard for "will a lot of crazy and sometimes legendary stuff get made by unknowns for this platform" is wether or not a high-school developer can get a game onto it. Someone without a company, resources, or business sense but with a lot of time and passion. I don't really feel like that fits consoles right now, there are too many hurdles for that type of developer to get something on PSN, XBLA or Wii Ware. There could be an argument that XBLIG is a place for exactly that kind of developer, but I don't know that much about it.
I do know though that the PC / Web and Apple App Store are bursting at the seams with those kinds of developers.