Yes, but nothing crazy.
1280x720 should be cheap and look good on a small form factor (6.5 inches or smaller).
I have an 8-inch Samsung 1280x720 LCD tablet that I got for $180, and the screen is light years better looking than the 3DS or Wii U tablet. Like waaaaaaaaaaaaaaaaaaaaaaaaaay better looking and this is a bargain basement tablet that's more than a year old.
The next handheld if they go the Fusion route is basically the beginning of a new hardware legacy really too. It's not the GB-GBA-DS-3DS line anymore, it will likely have to be the first Nintendo handheld that can handle the "big boy" games, meaning the real 3D Mario, 3D Zelda, 3D Metroid sequels and everything else Nintendo's designers want to do.
So design priorities will have to change. On the plus side for Nintendo a lot of this stuff is very mature, cheap technology by now ... yes a 1280x720 LCD display 7 ars ago would've been cutting edge, but today it's very, very cheap and heavily mass produced.
I think two screens and 3D is out too. Maybe they'll have a way where you can hold the system vertically and buy a controller cradle for 3DS/DS backwards compatibility mode though.
