They're doing well. Support is slower because they started later. Indie scene has been thriving on the PS3/360 for a long time now. Support on the wii was very limited; stand outs were world of goo and that game where you control wind.
They're not as aggressive as sony or Microsoft but right now I don't think they have a ton to gain through that, now they're just building up quality support and paving way for indies to succeed on their platform.