As I see it, a short tele zoom like the 70-200 is equally useful on a crop body as on a full-frame body. If you want it now, buy it and use it on the 550D. You will not be missing out on anything.
As for a normal zoom, I'd advice differently. What is a normal zoom on a full-frame camera (ie your typical 24-70ish lens) does not make sense as a normal zoom on a crop camera, it simply does not go wide enough; a 17-50ish lens is a good normal zoom for a crop camera but simply won't fit a full-frame body at all. You can in principle use an ultrawideangle full-frame zoom like a 16-35/17-40 on a crop camera, but they really are a bit short for use as a normal zoom. I'd get a good dedicated normal zoom for the crop camera and expect to replace it outright when moving to full frame. The Canon EF-S 17-55 is best of breed, but has an L-level pricetag; there are cheaper third-party options out there that are quite good.
As for wide angles, this is even more true. Buy for the camera body you have now, replace it along with the camera body when the time comes.
As a side note, I see you are planning to get a Canon 50/1.4... I just want to point out that while it is decent optically, its build quality leaves a lot to be desired. The autofocus mechanism in particular is hideously vulnerable, one knock in just the right place on the front of the lens is all it takes to break it. A friend of mine killed two of these in within a couple of years. Do get (and use!) the optional lens-hood if you buy this lens, it gives decent protection against this kind of mishap. I'd also take a long hard look at the Sigma 50/1.4 if I were you, by all accounts it can be a very good lens and it is far more robust than the Canon offering.