Both the Nikon D90 and the Canon T2i (Canon EOS 550D) have some great deals on right now, and I've been getting a lot of questions from readers on which one of these DSLR's to buy.
I did a video post on Youtube to try and answer the question for you.
The short answer is...
If video is your primary concern, then go with the Canon T2i. The T2i is a better DSLR for video. It has manual control options, an external mic input, and 1080HD.
If photography is you primary concern, then go with the Nikon D90. The D90 is more of a photographer's camera. It has better high ISO image quality, better auto focus, and is built better.
For more elaboration, watch the video. :-)