The biggest thing here for me is the Celeron M vs. the Core Solo. Celeron M's run very hot, have poor battery life, and don't have that much processing power. There isn't even a point in having a gig of DDR2 RAM if your processor isn't even good enough to make full use of it.
In contrast, the Core Solo is fairly recent technology, runs pretty cool, has fantastic battery life, and can at least match a Celeron M in processing power. Seeing as how the HP laptop is also $120 cheaper, I'd say to go for that one, as long as you're willing to stand in line for a very, VERY long time.