The latest issue of Nintendo Gamer magazine dishes some new details on how Assassin's Creed III will work on Wii U, and you know, it does sound like a nifty little tool. Yeah, I said "nifty."
While the Wii U tablet doesn't serve any major gameplay purposes, it does attempt to streamline in-game features by separating them across two screens. Where you might be running around as Connor on the TV, the tablet can house the Animus display, letting you access both Connor's world and the Animus simultaneously. The tablet can also bring up a persistent map and act as a navigation tool.
The touchscreen could improve weapons selection during combat as well, letting Connor switch between dual-wielding and a single weapon with just one touch. Tapping the screen can also provide an alternate view to Eagle Vision using the accelerometer, if... you don't like Eagle Vision, for whatever reason.
Database entries can also be viewed through the tablet, turning it into a digital encyclopedia of sorts, in case you'd rather do your reading through the peripheral rather than your TV. If a new codex entry appears, you'll be able to check it on the handheld screen rather than bring it up on the TV and potentially interrupt your game.
Sound like a convenience or just an unnecessary hassle? Guess that depends on how good you are at balancing your attention between two monitors.