Crop cameras can go a long way - granted nowhere as long as FF cameras. However, this will probably be the best Canon crop camera for those starting out and needing something solid on a budget. The only other prosumer crop camera with pro line features up until now was the D300 and D300s. The 7D now gives the Canon crop folks a worthy competitor.
A lot of wedding shooters starting out get invested in crop lenses like the 17-55, 60 macro, etc. So, having a top notch crop body is a good idea. If it performs well in the IQ department, it should be a wonderful implementation.