I haven't read thru all 5 pages of responses but I agree with the suggestion of a 50mm lens plus a circular polarizer for outdoors in broad daylight. I also would put a battery grip on it, just makes it feel better balanced, or at least it does to me. I have a T3i and the grip just made me feel better about it. Probably would help to balance the camera with that super zoom anyway.
Save save save, and get the 60D at some point and then keep the 550D as a backup. Acquire a couple of more lenses, and get out there and enjoy photography!

