Well unless you're against 3rd party lenses, the Tamron 24-70 2.8 is a pretty nice lens for about 1k.
Nice! This review [dpreview.com]
indicates that it has vignetting/barrel distortion issues, though.
IIRC with a Canon/Canon combo the camera autocorrects for this using a saved profile for the lens, which I assume isn't the case with a 3rd party lens.
That Tamron lens looks wicked for someone who regularly goes in and post-processes images - I'm too lazy/busy, though.