it's always good to get opinions from as many people as possible so i'll chip in
Core 2 Duo has BETTER battery life, not worse. it may be insignificant and within margin of error (<1% more battery life) but it certainly is not worse.
if you're looking into getting 64-bit vista (or another 64-bit operating system) then get C2D. Core Duo is 32-bit, wheras Core 2 Duo is 64-bit. C2D is also about 5-10% faster, on average, clock-for-clock.
the CPU can be replaced so if you find a good deal on a Core Duo, go for it, and if you need 64-bit/faster processor, you can drop one in down the line.
the GMA-950 isn't a bad igp; you just need to have more ram. if you have 1gb of ram, you shouldn't have any problems with it. especially seeing how you won't be gaming.
i'm typing on a hp dv2000t and really like it. the build quality is pretty solid, it's portable (14" widescreen, i like the way it looks, and the keyboard is perfect. my dad has a lenovo thinkpad t60 which i think is an amazing laptop but i don't think a new one would be in your price range. i've heard good things about apple's and the ones my friends have look good too. again, your budget probably won't allow for one.
what i think you need is any core duo (you really won't see much performance difference between the 1.66 and 1.83 or 1.83 and 2.0), 1gb ram, 5400 rpm sata hdd, good appearance, 14" (for portability), and integrated graphics.
you never mentioned what you'll be using this for, btw.
EDIT: you don't need bluetooth either...what are you gonna use it for?