I currently have a Canon 350d and a Canon HV20 HD Camcorder and I would like to upgrade to a single device that can capture both high quality stills and full HD movies at 24fps.

My preference would be a Canon and after a bit of research I've come up with the following options - 550d, 60D and 7D. I will mainly use the camera for family shots, holidays and the odd landscape pictures and to capture video of my two little girls... I would like my next camera to be last me a good 5+ years and I don't want it to be outdated in the next year of so.

Also, given the young family, I can't really lump a load of equipment around with me, therefore I would appreciate thoughts on a good all rounder lens that would cope well with still and movies to cover the above.

Budget is around 1500.

Thanks in advance.