i don't see publishers dropping support of HD consoles. Not until X360 games sales fall through the floor.
Perhaps we'll just see a whole host of safer titles and maybe more companys push multiplatform download games (wii, PSN, XBLA) as one alternative.
You'll see safe big titles, and downsized other titles that can be ported to the Wii. Much less exclusive HD games, everything will have a Wii version.
I think the ones to move to PSN/XBLA/Steam will be the smaller developers who don't want to take a chance on a retail game bombing.
Re: the STUPID arguement put forth by Nthings that best teams on Wii would be more successful, lets look at the third party performance on Wii...
Carnival Games - best 2k studio? If you don't count Rockstar then maybe internally.
Big Beach Sports - best THQ studio? Nope
Mario & Sonic - best Sega studio? hardly
Guitar Hero - port of a PS2 game,
Boom Blox - good game that bombed, and EA is fucked now although not as a result of this
Rayman Raving Rabbids - #2 and TV Party bombed like no tomorrow once they weren't there on launch. Not surprisingly Ubisoft now focusing on Petz & Imagine games for Wii. And if Red Steel did so well why isn't there a sequel yet? Because it's not viable.
DeBlob - failed miserably despite being good
Game Party - cheap as shit game from Midway that did decent
I'm still yet to see anyone with indisputable proof that putting your best efforts on Wii gives you any sort of positive result. The reality is you either put out shit at low cost and try to make money that way or fail. Anyone trying a big budget game on Wii is going to get stomped down by not only Nintendo's marketing and absurd brand loyalty, but also by retail who aren't going to take a punt on something unknown when they can stock Nintendo titles and shitty ports/shovelware that will move off the shelf.
Anyone saying otherwise is just talking fanboy shit.