Buy the old, non-IS, macro and save that extra cash for another lens.
I was thinking of that, but I do a lot of walk around macro (I borrowed my brother's 100mm macro, the old one, for a long time and used it a lot) and I was thinking the IS would be very nice. The difference is only about $400 right now.
I'd like to actually see how much the IS helps out, but from reviews I've read it does seem to make a difference. Since not all my macro is taken on tripods, I'm thinking it would be a good thing.
The 100mm macros and 135L are really different tools. Since you said you need a macro, I would agree with Doug's recommendation to get the older version and put the savings towards another lens.
I felt like my 85mm f/1.8 really came to life on the 5D, you could pick one of those up along with the older 100mm macro for about the same price as the 100L. Just a thought...
What other lenses do you have and what types of improvements are you hoping to get with your new kit?
Yeah, I realize the 135 and the macro are different tools

From what I read about the 135 it's just amazing and I'd like to get into candid photography, it's a great lens for that. I'll probably just stick to the macro for now though.
I currently own the 10-22 (which I'll sell if I dont go with the 7D and get the 5D Mk II, which is the current plan), the 50mm f/1.4 and the 100-400.
I'll probably sell the 10-22 and buy the 24-105 with the camera when I get it. If I really miss wide angle, I'll buy the 17-40. Depending on how happy I am with the 24-105, I might end up selling off my 50mm as well. Really, for most of the photography I do, having a 24-105 and a 100-400 is about all I need. I was also thinking about picking up the 24-70 f/2.8 again, I owned that for about 8 months and liked it. If I do that, I wont get the 24-105.