Perhaps an alternative might be the new Canon T4i? It's not a full frame, but is apparantly pretty good.
I don't have a huge investment in glass, but like you my family's point and shoot cameras are Canons, and I treated myself to a Canon T1i a couple of years ago (thanks AirMiles!) partially because I had a couple of EF lenses. Since then I've bought an EF L-series macros lens and currently lust after the EOS 5D III. Alas, I only have so many shekels to spend, so I suspect that I'll be acquiring a EF 24-80 f2.8L II before I buy a new body.