You know, I said this before, and I promised myself not to buy anything till 6 months later. This was September of last year. And then I went on a buying spree after breaking my Nifty Fifty. 430 EX II + 17-55mm IS. I think I have my ideal lineup for what my money can get. The 70-200L (any one of the 4) will require a giant investment, and I'm guessing the cheapest one (the f/4.0 non IS) is probably not gonna be a big enough upgrade for me over my cheap 55-250 so it means I'm looking to drop close to 1k to advance the next level. That or a new body (7D?).
So yes, go out and take some photos. You'll be happy. I'm looking at my first real shots with the 17-55, and I'm drooling over the sharpness. WOW.