There hasn't even been an official acknowledgement saying that the iPad 2 is coming soon.
I would buy the cheapest iPad you can find now and enjoy it, maybe even buy used.
All the speculation about things like a higher resolution screen, faster processor, more memory, SD slot, etc is all simply speculation based on either nothing at all or very inconclusive "evidence."
Buy now, enjoy, and sell it for close to what you paid if you still want the iPad 2 when official specs finally get announced.