I'm thinking it depends on your graphics card. I have the nvs 8400m in me T61 and it's giving a heck of a lot of problems. For example, connecting an external screen means fudging with the xconf. Also screen brightness doesnt work.
Probably all the fault of the proprietary drivers, so it just goes to show that you'll have to pick your laptop wisely if you want Linux running on it.
My wife's got a Lenovo laptop and upfortunately the trackpad is appalling. Not just worse than my MacBoook Pro, but worse than the bottom of the range Tesco/eMachines laptop that she had before it.
I have heard that Intel Atoms with internal graphics should be avoided since the graphics on those is not actually Intel's doing, though my eeepc with an Atom/internal graphics works fine.. maybe I got lucky.
I wouldn't recommend getting a Lenovo with an Atom anyway though, if they even sell anything with Atoms (mostly just from a "If you are going to spend money, spend some money" standpoint.
The only problem I've had was connecting to an SSTP VPN but that was resolved easily with an ssh tunnel.