[youtube]ojRzPyuJFcU[/youtube]
The iPad 2 has more RAM and better processor than iPad 1 which can be demonstrated from the above video where the multiple tabs in safari starts loading again (not all but most of them) while browsing when compared with the browser in iPad 2. Also, the checkboard sometimes seems to be annoying when you scroll a page and the other content appears after a few seconds. In the video, Tipb has considered that the iPad 2 has 512 MB of RAM (not confirmed) but certainly more than the first generation. However, iOS 4.3 brings nitro engine in safari like that of Mac OS X which boosts the overall performance of the browser.
[via Tipb]