Ok, let me just say that the hd2 is a huge (but slim) phone, I mean like really big, not for the average person but if you like watching movies on your mobile and thats your thing then knock yourself out.
Personally though I would choose an HTC over a Blackberry any day. HTCs just feel so well made and worth the money. They are also bringing out some really nice smaller phones like the desire and the legend. These are also android like the hd2 and boast nice big screens. The nexus one is also a very nice phone which has just been released and is probably the one I would go for.
Price wise though the Blackberrys are much cheaper, and at the end of the day after 5 months and the "new phone" novelty (and smell) has worn off the price will be the most important thing.
Choose wisely and research all phones thoroughly.