I'm going to be in a similiar situation as you in a couple months and I'm really looking at the Dell line up with particular attention to the Latitude line. They're the business grade computer and seem to hold up really well. I know it's going to cost me more up front but I'm hoping it'll cost me less in maintenance, downtime and frustration in the long run.
I've looked at the Toshiba's Best Buy has and none of the one's I've seen do better than 1024x768 on the built in display. For a laptop to be a mobile desktop replacement for me the display MUST do 1280x1024 natively.
Let us know what you decide on and what you think about it after you've had it a while.
EDIT: When I said 1280x1024 I should have said more than 1024x768. 1400 x 1050 is fine with me