$1000 is enough to get you 17" of Core 2 Duo glory...
They had to skimp somewhere to hit that price. There is no free lunch.
Also, laptop warranties are (imo) overrated, unless as Mike says you get a 5 year one. I've found most manufacturers offer three year warranties, and stuff either breaks really early (within the default warranty) or after the extended warranty runs out.
Some other things to take into account:
Resale value (at the end of your intended span of use)
Virus protection costs (iirc there are some free virus protection things, but it's not something I've paid a whole lot of attention to)
Software cost and availability (there's a lot of free stuff available for *nix systems [including osx] that can keep costs down)
Personally I went with a macbook, but I had a developer discount and absolutely need mac-specific software, so my situation may be a bit different.