Personally for use on 60D, I'd prefer the EF-S 17-55/2.8 over the 17-40L. IS and a full stop faster... might be sharper corner to corner, too. It's not an L... but some great lenses aren't. If you don't need f2.8, the EF-S 15-85mm IS is a great walk-around lens.
I don't buy into the idea that 24-105 isn't a good choice for use on a crop camera. It depends upon what you are shooting and the focal lengths you need. Personally I would buy an inexpensive 28-135 instead (except you already have an 18-135), it isn't as well made or sealed as the L, but pretty much matches it in all other respects: USM/focus speed & precision, IS, close focusing ability, and perhaps the most important factor, image quality.
70-200/4 is a nice lens, but not really a whole lot longer than your 18-135. Only you can say if 70-200mm would be long enough. I use a 70-200 a lot on my crop cameras, but I also use a 300/4 and 300/2.8, both with and without a 1.4X teleconverter. The 100-400L is a versatile lens, I'm just not a big fan of push/pull zooms. There are some good alternatives: Sigma 120-400 OS and 150-500 OS are both considerably cheaper than the Canon. Both are more traditional zooms, with separate focus and zoom rings. At their longest focal lengths, they don't deliver quite as much contrast and color saturation as the Canon, but both of those factors are pretty easily dialed up in Photoshop or whatever you use for post-processing.
Frankly, on these longer lenses IS is awfully nice to have. Especially when using them on a crop camera. IS (or OS on the Sigmas) makes possible some shots you'd struggle to get without it. Something to think about.