If you've been following the DSLR scene, you should be hearing about how Tamron has really stepped up with a few newly designed lenses. The quality is far from what they were a few years back. One popular lens grabbing some attention is the new Tamron 24-70mm F/2.8 DI VC mainly due to the fact that it has Vibration Compensation (image stabilization) for just $1299 while Canon offers their 24-70mm F/2.8 (without IS) for $2299 (seen here).
Just a few months ago Tamron announced a new 70-200mm DI VC lens and it's finally available. This new lens offers another solid option versus Canon's 70-200mm F/2.8 IS that typically runs for $2499. The new Tamron 70-200mm F/2.8 with VC will be available for Canon EF, Canon EF-S, Nikon F (FX), Nikon F (DX), and Sony Alpha for just $1499 via B&H (click here)
Tamron 70-200mm F/2.8 SP DI VC
Now if you're really hard set on Canon glass, the 70-200mm F/2.8 IS II (normally $2499) is currently on sale for just $2099. I just recently picked up this lens for $2500 dollars so i'm a bit upset, but you can get this deal up until January 5th (found here).
Canon 70-200mm F/2.8 IS II