[PB PM]

If microphone input is important, and your budget it limited, don't even look at Nikon. The Nikon D7000 is the only affordable DSLR with a mic input and it costs $1200 body only, if you can even find one in stock. As for the 60D, the biggest difference between the two cameras is the swivel screen and better AF performance, because on the 60D all 9 AF points are of the cross type (better AF sensors). The 60D has more external buttons, for faster changing of a number of settings but those appeal more to people who are really into photography. Also, the 60D has gain control over audio. Many Canon users are calling the 60D the "Super" T2i, because they are so similar.

I had mixed feeling about the T2i from my use of it. My first piece of advice is take the camera out of evaluative metering mode, use center weighted instead. The T2i does take practice, because the resolution is so high the margin for error is small. Low end crop sensor lenses will give poor performance and images will look a little soft unless you reduce the size of the images. That seems to be common among all the 14+ MP crop sensor cameras though.