can someone kindly advise me the pro's/con's of getting a d90 over the newer canon 550d?

i was leaning towards the d90, but from shopkeepers they say the 550d is more worth it. video mode is better, canon lens cheaper and service better.
in terms of photography, i hear the d90 is probably slightly better, but by how much? suppose to be better in lowlight conditions?
i understand that the d90 is aimed at prosumer ppl while the 550d is more beginner-dslr, what makes this so? would it mean d90 has more configuration or better specs?
i currently use a 450d and will sell it, just deciding between d90 and 550d.