Notebook 'minimums' for playing Blu-Ray movies?

I'm wanting to get a notebook/laptop [not "netbook"] for my wife. Her demands are pretty pedestrian; a few business apps, photos & avi's of the family kind, but also occasional movie [distractions when traveling].
I don't want it to be quite obsolete on Day 1 so I'm looking at insuring that the DVD drive is capable of reading Blu-Ray DVD's, and that the graphic subsystem is up to snuff. Since "Vista" seems to be on all the newest Notebooks, I assume it is going to be more sluggish than a leaned-down WinXP.

Is a high-powered graphics 'card' a necessity in this case? Memory is cheap and most of the newish units can go to 4GB so I'm thinking of doing that full-up immediately. Will that help smooth things out if the graphics subsystem is just 'ordinary'?

Also, if her pick of a Notebook does not have the most up-to-date DVD, is removing/replacing that DVD cost-effective or am I going to get hammered on the cost?

Thx for the collective wisdom!
z