Boy, I hemmed and hawwed over this one for a long time myself. In the end, the combination of fast glass, IS, ideal "walk around" range and excellent IQ on the EF-S 17-55 f/2.8 won out over my desire to stay with full frame compatible lenses. It was the best lens for the job on the camera body I have now (40D); the future will have to worry about itself [] I don't regret it a bit and have even added the EF-S 10-22 to my kit for much the same conclusion; best lens for the job.