Unless the WiiU does insanely well, I don't see how that's viable.
The price of making a 'AAA' Durango/Orbis game isn't going to be multiplication of the PS360 games. Unless the WiiU install base completely dwarfs the combined PS4/XB8 installbase, it's not going to be anymore viable to make games on there.
If anything, the 3DS is the only 'haven' left.
Multiples of Wii U? That's difficult to say. Budgets will continue to increase, however, and at some point all games and franchises will reach a point where they cannot feasibly continue to climb upward in cost.
Further, the rate at which games reach this point will vary by genre and franchise; obviously Call of Duty, for example, can climb for a much longer period than can Bayonetta, or even Metal Gear Solid can.
And I think you'll find, generally, that there are a good number of Japanese franchises hitting their "cost ceiling" at around the PS3/360 threshold. Heck, many (such as Disgaea) met that threshold before then, and others met it so long ago that they have long since moved to handhelds.
By contrast, the Western solution to a franchise that can no longer escalate in scope and production value is to simply put the franchise to rest. It doesn't go to handhelds, or become a scaled down affair like Disgaea on PS3 in Japan, it simply stops being made, with the distant hope that some day it may be reborn as a retro franchise on Xbox Live.
I really don't know enough to say if there are
a few franchises that will be unable to make the leap to PS4/720 or
a lot of franchises that fit this description, but we may find out. Western franchises, as said, will likely just cease to exist rather than be relegated to a single, weaker platform like the Wii U -- but Japan doesn't seem to function in that manner, so this is at least a possibility.