Don't worry too much about video in a DSLR, especially about zooming while doing video. You have to manual focus the video unless you hit the focusing button each time you want it to focus, it doesn't do auto focus tracking.
T2i vs the XSI is a decent comparison. From the review I read, the T2i has improved upon areas such as white balance and exposure metering. The megapixels is a wash unless you buy lens that can resolve 18MP.
Truthfully, if you find a great deal on the XSI and spend the extra money on lenses then the XSI is a better choice. The difference in lenses make a bigger difference in image quality.
i want to buy new dSLR camera. this will be my first SLR camera. i am buying this just for hobby. i am not taking photography as profession. my interests are landscape photography, family portraits and some macro photography. after doing lot of reviews i came to following conclusion (i hope,they are right!) - i need entry level dSLR...from canon...i came down to rebel xsi (450d) vs. rebel t1i (500d). after reviewing my needs and comparing prices, i decided that it is not worth for me to put more money in t1i as only advantage to me was video capability that is only 20fps at 1080p. and then canon released rebel t2i (550d). that increased my confusion. comparing specs, t2i is definately better that xsi. but higher pixel values, more ISO range, new digic 4 processor - is it realy useful for my needs ? now t2i has 1080p video capabilities at 30fps which is realy good. but i found some reviews that states issues with zooming while video shooting and lens noise being recorded during video recording, is it realy true ? so far, CNET has not put full review of t2i (which i don't understand why?) this whole thing left me confused. so help me with my first dSLR.
thanks in advance...