Let's hope that Nintendo puts a little more effort into updating the most successful consumer electronic device of all time than just making a portable version of what clearly ISN'T the most successful consumer electronic device of all time. That would be more stupid than lazy, and believe me, it would be freakin' LAZY. If the next Gameboy was nothing more than a portable Gamecube than I would be displeased, backward compatibility would be one thing, but failure to innovate beyond that would stink and be uncharacteristic of the Nintendo I stand by. I WANT one of those Sharp 3D screens with a big wide display, I WANT, nay, NEED some sort of online/network option. It's too late for Gamecube games to take advantage of any of these things, but games developed specifically for the next Gamboy could and should use said features to thier fullest, assuming it has them (knocks on wood).
Media is a significant issue. Not only are GOD's completely bare and free of ANY hard-casing or protection, the Gamecube itself is constantly streaming data off of those little badboys to cut-down on load times. It's a great idea and a brilliant feat of engineering, and it was all made possible because they were designed and created without portability romotely as issue. At least PSP designers know to anticipate this problem from the get-go; but, barring some major advancement in battery technology currently unforseen a game like Metroid Prime (which created THE gold standard in load-time avoidance) would rip some piddly little battery to shreds. BUT a funny fact about the Gamecube's architecture is that the A-RAM has been ubgradeable since day 1, that would significantly reduce load times therefore allowing for a more economic use of the disc drive allowing for a longer battery life. The only problem is getting this to work for older GCN games assuming proper code isn't there already, which I doubt. Then there is the memory card/need for data storage, another inconvenient reality that comes with using an optical media. How many Reggie cracked about the PSP's memory sticks? Those jokes are funny because having memory sticks suck. Built-in hard-drive or bust. It wouldn't even have to be that big since virtually all Gamecube savedata was designed to be compact and contrite. 512 MBs of built-in flash memory would be more than enough for Gamecube saves, leaving more than enough room for next-gen GB games, which there had better be.
What about the controller? Gamecube has gargantuan shoulder buttons, portruding analog sticks and a rumble so fierce that it may have rendered me steryl. Granted the rumble can be romoved, the buttons shrunk the C-Stick tucked away somewhere (convenient) and the Z-button can go anywhere. That all seems reasonable, no worries there.
Maybe there should be something that greys-out any and all Gamecube multoplayer options. Even if they could find some-way to recreate and emulate the 4 controller port aspect over a wireless network, you'd still have the 4 screen split on every one's system. That might be funny at first but get-old quick.
No handheld anywhere would be able to display much better than 1/2 the Gamecube's standard resolution. Games like Wind Waker and Metroid Prime 2 might look awfuly strange on a Gameboy.
It had better have a clamshell design if only to protect the display. Screen cracks are no good, and a unit like the one I'm describing would cost alot more than 60$ to replace.