Currently, my wide angle lens is a Canon 17-40 f4L.   I am wondering if I should look into the Canon 10-22 or one of the new APS-C size WAs from Tokina (12-24 f4) or Sigma (10-20 f4-5.6).  Anyone have any of these?  I am primarily interested in using the lens for landscape photos.   Do yall think the 17 would be wide enough for that?

If you're planning on doing really pro work, I'd say go with a prime or tilt-shift lens.  The 17-40L is a great lens, I think it's wide enough for wide angle photography.  I guess it depends on how wide you need to go.  Check fredmiranda.com for lens reviews, I'd watch out for barrel distortion with those really wide lenses.  Big no-no for landscape photography.

I have a 17-35 F2.8 that I use and love it, never felt a real need to get another one as this one handles everything I need it to.

Quoted: If you're planning on doing really pro work

I am not a pro by any means---just a hobbyist.

Though I'm a Nikon shooter, I'd say go for the Canon 10-22. I picked up a Nikon 12-24mm f/4 a couple months ago off eBay and have been extremely satisfied with it. Up until then, my widest lens was a Nikon 24mm f/2.8, which worked out okay for film, but it got to where even with film, I started wishing for more coverage. Thus, when I went to digital, I had to get a wider lens, the 12-24 deal came up (35mm equivalent is 18-36mm, of course), and I'm now very happy. Personally, I recommend staying with the OEM's lenses if you're a pro or critical amateur, but if your needs aren't as stringent, then an aftermarket lens like the Tokinas represent an easier buy-in. HTH. Happy shooting (pun intended).

I've had the Canon 10-22mm for about a month.  On my Canon 20D, that's equivalent to a 16-35mm lens on a full-frame film or digital SLR.  I really like it -- you can get an entire room in the photo for interior pix, and really expansive landscapes outside.   Very little distortion -- straight lines stay straight at the frame edges.  Get the Canon lens hood to go with it.

The Canon 16-35 is the lens to get if you ever plan on going full frame. That being said I use the 10-22 with the 1.6 crop.