Rol's thread awhile back described it perfectly.
Wii:
Initially it was the default loser due to GC and no one put money into building quality tools to make quality games on the device. The instead put MILLIONS into dev tools for PS360 as they knew they would be the dominant consoles.
Then, Wii skyrocketed to success and devs took a 2nd look; they didn't want to lose out on the now fast growing Wii user-base, so they started to quickly port crap based on PS2 tools (or the few who had GC centric tools) they already had produced. This succeeded and a few of these titles made them tons o' money.
Then it was time to start the next round of games. The decision became do they A) basically toss out the millions spent on making HD gaming dev tools to while spending more millions to make a Wii based dev tool that allowed porting to PS360? OR 2) do they continue with the HD twins as primary benefactors while Wii gets a shoddy upgraded dev toolkit for lower end games that 1 out of 5 will probably be massively profitable? They chose the obviously smarter (from a fiscal point of view) option after considering the costs and the fact that Wii never broke the 50% marketshare so from a potential userbase, there was no big gain to spend millions in making new tools for Wii for the big IPs.
Thus, no major 3rd party shift.
Now for N6:
New gen requires all new tools, so regardless of which console is the focus, millions will be spent.
3DS is already demonstrating Nintendo's willingness to go to far better technology.
3DS is also showing a strong 3rd party relationship with Nintendo.
So, the more obvious conclusion is that Nintendo will produce a far more capable machine that should be more like PS2 to Xbox than Wii to PS360 when the other consoles launch, thus removing the inability to easily port if needed. They will also be building off of Wii's success and the indirect success of DS and soon to be 3DS. This should mean that 3rd parties could very well build their tools to be N6-centric with the anticipation that it could be modified for a relatively small % of money to work on the PS4 and neXtBox. Meaning it will have SNES level 3rd party support, however, that does not mean a PS2-like level of exclusive 3rd party games. Based on this gen's performance between PS360, all big games of future may be at best timed exclusives.
