dell is amazing about their laptop warranties. when i had a problem with the USB in my laptop (it broke, not sure why), they had a guy out the next day to replace the entire mobo.
further, i had a dell laptop that "broke" from time to time -- keyboard got bad, harddrive crashed completely 3 times, LCD was bugging me, palmrest cracked -- this occurred over a course of 2 years or so, as i use my laptop as if it's my desktop (it's my main machine), and when i last called dell to complain about my hardware in that particular laptop (inspiron 8000), the tech support person said, "it looks like you're having a lot of difficulty with your laptop. we'll replace it with a newer one under your warranty."
SCORE!
needless to say, i've been using that replacement laptop (inspiron 8500) since 2/2004 (it was a big upgrade from the original and considering i didn't have to pay, it worked) and i'm happy with the fact that i didn't have to consider buying a new laptop to replace the 8000 instead (as i was going to since it was about 3 years old).