Photography Enthusiast/Budget Filmographer - D5100 vs T3i?

Hey guys/gals. I've been a Nikon guy for a while now, and recently have been shooting with the D3000, and a little bit with a friend's D5000. I've been renting video equipment for some video shoots and interviews, but I used a buddy's D3100 and it was fantastic for shooting video, so I started looking into DSLR's for my video shoots.

Word on the street is that Canon dominates the DSLR video market. I don't have a huge collection of Nikon lenses, so I'm not completely against switching to canon.

I'd like to come here to ask the Pro's what I may find in the differences in usage for both video and normal photography (I do a decent amount of indoor shooting, as well as some outdoor (3:1 ratio)) that I'd find between the two.

Or is there something else I should have on my radar?

Thanks guys/gals!