ugh I don't know, these were all things we chose to pay extra for as options. And I can't check, because we were ordering it through my dad's office (they get a discount)... I can look it up tommorow. But I need his password to access the site.
Just your luck, I did a little research, my analysis is not very helpful however I am afraid.
In a display of google prowess i have discovered:
HP
1.8 GHz Core Duo, Model Txxxxxsomething, don't know since all the product page said was core duo. I am on a 1.8 GHz Core Duo right now on my mac, very nice, respectable proccessor. Dual core is an advantage if you are going to be editing videos/encoding this or that/ etc. I assume you are looking at the Nvidia GeForce 7400 option, which is respectable, a good laptop GPU. They are lying when they say "graphics card", however. It's integrated, but it does have dedicated VRAM which lightens this disadvantage somewhat. The GeForce 7400 is a respectable GPU and you could run recent games on decent settings. The lightscribe drive? What a waste of money, don't bother. I assume you realize this.
Dell
The processor is also a Core Duo, which is cool. This one looks more appealing due to the optional TV tuner card, couldn't find make/model for it however, but a tv tuner is a cool thing to have if you can afford it. They say "optional dual channel memory". I would hope in this day and age that "dual channel memory" is a given. XP Media Center Edition is a nice plus, but it doesn't have a whole lot of use if you don't go for the tuner card.
Both of these are pretty respectable machines. If you go with the tuner card and MCE then I would reccomend the Dell, otherwise choose the one with the lower cost. I couldn't find info on the Dell's GPU, so if you're looking to game, the HP is probably the better option. Given the option, go with the Core Duo models on either of these. I haven't been keeping up with how these Core Duo's stack up against comparable AMD's like the Turion X2's, so I can't say offhand whether going AMD would be a better choice. The price point is probably better, so it may be worth it to look into an AMD system.