air travel with T2i

I will soon be traveling from Chicago to Miami by air. I've never flown with a dSLR, and gear, before and was wondering what kind of hassle is involved with the SLR.

I will have the T2i with the 18-135 lens on it, and my 70-300 IS lens also. Will the camera and lenses have to come out of the bag like a laptop does?

Will I be separated from my camera stuff in order to deal with the new-style x-ray machines?

I have the Canon 200DG bag, will it fit under the seat in an American Airlines 757?

Any other advice or considerations that anyone could recommend?

Thanks!

km