The internal hardware of the iPad 2 is likely to have a more lasting impact than the changes to the chassis. Like its recent rivals, the iPad 2 features a dual-core processor, in this case codenamed the A5 and running at 1GHz - this is backed by 512MB of RAM, the same as the iPhone 4.
Despite having less RAM than many of its rivals - most of which boast at tidy gigabyte of memory - the iPad 2 never feels slow - Apple claims that the iPad 2 is "up to 2x faster" than the previous model. Although we can't say we noticed many apps running twice as fast, everything from Safari to GarageBand definitely ran faster on the newer model. This proves more of an advantage in the home than out and about; bearing in mind how many apps are effectively just pretty, stand-alone web pages, over 3G the connection tends to be the limiting factor in how fast apps run.
The graphics in the iPad 2 are also much improved over the previous model. The "9x faster" than the iPad claim may seem bold but it seems to hold water, with the PowerVR SGX 543MP2 chip embedded in the A5 making mincemeat of any game or app currently available. Epic Games' Infinity Blade is far and away the best-looking game on any currently available tablet, and on the iPad 2 it has a massive boost in fidelity over the iPad, offering much improved rendering fidelity in addition to a higher framerate. We've seen less good-looking PS3 and Xbox 360 games.
That said, its prowess only matches that of most of the other dual-core tablets that will soon be available (Motorola Xoom, BlackBerry PlayBook, Optimus Pad, HP TouchPad, Samsung Galaxy Tab 10.1) so it's not a technical tour do force. However, the sheer ubiquity of the iOS platform means that iPhones and iPads to tend to lead the way when it comes to the latest games so if that's your priority you may be better of sticking with Apple. The wide range of possible hardware configurations for Android really hurts it here - the Apple iOS ecosystem has its faults, but fragmentation isn't one of them.
Apple has managed to gain these performance improvements, and pack this faster iPad 2 into a smaller space, without impacting on battery life. The original iPad impressed on this front, and the iPad 2 runs with that. It's perfectly possible to get a few days of casual use without having to charge the system, and over 10 hours of continuous use - an improvement over the iPad, which was already the class leader, and more than we're expecting to see from the best of the new comers (though obviously we'll have to confirm this when they do finally arrive).