After jailbreaking your iPad, you can install SNES4iPhone, which will not only play SNES romz—it will open the Bluetooth stack, allowing you to play Mario with a Wiimote. Nintendotacular! [Instructions via SwagLikeMe via notcot]
When it comes to my iPhone 3GS, I don't think I'd jailbreak it because it has pretty much all the features I want...
But if ever I buy an iPad, without a doubt I'll jailbreak it even if it voids the warranty. There's so much potential for it, and if Apple doesn't follow up on it, I'm fine with jailbreaking and using it to its fullest potential because someone else took time to unlock its potential.
PS: Anyone else think Jobs is losing his mind? Seriously.