It would be a lie to say that gaming on the Android platform is at the level of that of the iPhone. It's not... but boy, things are a'changin fast. We've seen recently a number of developers that weren't interested in doing Android development change their tunes rather quick.
Android proliferation and market penetration continues to expand... and just recently HP announced Android on printers!
Ngmoco is one of those recent companies who have seen the light. In this case, it might have to do with the Google investment into their company as much as the Android growth but we'll take it either way.
MobileCrunch recently reported that Ngmoco has decided to do development for the Android platform. You can read a bit more here: Google’s Investment Pays Off: Ngmoco Building Plus+ (And Possibly Games) For Android