Oh hey, I'm famous! Yeah, I pretty much stand by my original statement that MS and Sony will always recieve the majority of third party support as long as they are making consoles and their 1st party games don't reach Nintendo-like popularity, Nintendo consoles will always be an afterthuoght for 3rd party devs. The main reason being they simply don't want to compete with Nintendo's major games, which have a stranglehold on the software sales.
However, that's not to say support can't improve. With the amount of support Wii got, that won't take much. I think the lack of success of Gamecube sort of wrote the death note for Wii third party support before the console even came out, since everyone expected it to get the same low sales, if not worse. Of course, there is also the gap in horsepower, but I think this is way overstated and more of an excuse than anything.
I think the next Nintendo console should get better support, now that devs have waken up to the fact that Ninendo hardware probably isn't going to be selling 20 million again any time soon.
