For years – decades – my advice has been to pick out the lens system first, then buy whatever camera body hangs off the back of the glass.
I bought a Canon T3i. The articulating screen is far better for video than the older T2i you are considering. Otherwise, the two cameras are identical.
I also bought in a hurry, adding a body to my system. I wish I had researched more and spent a little extra for a Canon 60D because of ergonomics, operational similarity to my 5D Mk II, and better control of ISO and white balance. The T3i will get the job done, but white balance, in particular, is buried in the menus because this camera is marketed towards amateurs who are not so interested in manual control.
Autofocus on the Sony may be a big deal to you, but it is a non-issue for most pro applications. In particular, if you are going to DSLR for shallow depth of field, auto focus can be a joke.
Another factor in favor of the Canon is ecosystem. Sony and Panasonic DSLRs look great on paper, but reviews don’t often address the real world where you may need an obscure accessory. For instance, I just bought a 3rd party intervalometer for the T3i off Amazon for $35. Now, any given model of Sony or Panasonic may have that functionality built in, but when you look at the big picture, you are much more likely to be out of luck once you stray from Canon or Nikon.
Since you are planning to do talking heads, make sure you have reviewed your audio plans 3x more than you are sweating this camera decision. Hint: in camera audio is not great. An on camera mic is even worse.
At minimum, you should add a Rode Video Mic Pro to your kit, along with an extension cable to get the mic closer to your subject. A lavalier is also essential for interviews.
Audio is actually more important than video. That’s why radio stations work, but see how interesting your TV is with the sound muted during a movie.
No doubt the Sony A55 is a beautiful camera. I just checked out the review on dpreview.com. I’m not familiar with the system overall, but one final question I would ask myself is, “Can I rent lenses?” It is nice to have resources like lensrentals.com, especially considering you could augment your basic package not only with special glass, but also additional bodies if you ever find yourself in a situation where you need multiple cameras (interviews being one). BTW – I see that lensrentals.com is renting Sony… so maybe we’ve landed back exactly where we started.