It's thinner, faster, lighter, and no more expensive than the original but is the second generation iPad worth purchasing if you already have an iPad or should you wait for the iPad 3? I'm not sure, but like many folks who already own an iPad, the iPad 2 is intriguing but a little underwhelming and certainly not an evolutionary step in a new direction. It's kind of like the iPhone 4G versus the iPhone 3GS: nice, slightly revised packaging and improved performance but essentially the same device with a mid-product upgrade rather than a complete overhaul. Will I get one? Maybe, but I'm not as excited about it as the first time.
Key deficiencies from my perspective:
Lack of retina display
Low resolution cameras
Thinner but still a bit on the heavy side compared to Amazon's Kindle
No SD slot
But still a nice product if you can sell your current model and buy a new one without losing a lot of money on the deal.