Looking to get my first DSLR after many years of being disappointed with the quality of compact digitals, especially when it comes to interior/flash shots, even with my 4 month old Canon S90.

(Which friends in the know and a shop pro or two have told has the potential to wow me, if I learn how to take pictures properly - I don't mean framing, I mean light, settings etc.) However:

I was hugely impressed by a friend's Nikon D90 last summer, but it might be slightly out of my price bracket - I was thinking more along the lines of the Nikon D5000.

Are the two comparable in terms of image quality? Will I be as impressed with the quality of the D5000 as I was with D90? It wasn't a pro taking the shots last summer, it was me or my sister (her boyfriend's camera), and it was point-and-shoot wow, almost every shot.

Any thoughts or advice gratefully received.