Web browsing and other apps are noticeably faster on the new one. You will get what you pay for in the long run. Having the first one available for now just adds another price point. I would however suspect that it will not be available much longer since they are no longer in production. Apple will in a few months also have refurbished iPad twos no doubt. In the long run prices will also drop with better competition. The question is what you are willing to pay and how long you want to wait. I suspect this Christmas season we will see a price drop on some tablets as competition becomes fierce and the weaker products become desperate.
Right now one of the big questions is will the screen bleed manufacturing issue and supply disruptions especially with flash memory effect apple and other tablet makers. I would expect a very tight supply if the retail launch goes ahead on the 25th. Online orders in the USA are now scheduled for a month delay.