same basic concept, but on a much more limited level. my P&S also had a manual mode, but the aperture settings are very limited. ive tried messing with manual focus but i just dont like it. it seems sharp in my viewfinder but when i open the pic full size its a little blurry. i find the D90s AF system to be fast and accurate so i let the camera do its thing.
i'm also a nikon fanboy

i personally dont like the look and feel of canon cameras. they feel cheaply made, even though that doesnt speak to their capabilities. unless your going with $5k extreme-pro cameras, you wont notice a difference between canon or nikon