Thanks for all the input guys. I'm pretty much decided on the 24-105L now. I got to play with both the 15-85 and the 24-105 today at a Best Buy. I love both, But I think I like the L a bit more, mostly because of the long end. I like the heft and feel of it as well compared to the 15-85.

Now, do I go for the 24-105L, or the 100-400L...

I think I shall decide that on Thursday once I get some hands on time with the 100-400L.