This is a very good deal. Having a decent graphic card may help in some situations as well. (Some CS4 programs can leverage GPU support.)
$999 - Lenovo IdeaPad Y550P(324156U) NoteBook Intel Core i7 720QM(1.60GHz) 15.6" 4GB Memory DDR3 1066 500GB HDD 5400rpm DVD±R/RW NVIDIA GeForce GT 240M - Retail http://www.newegg.com/Product/Product.aspx?Item=N82E16834146613
Ideally a little more ram might be helpful for video editing--but thats difficult to find cheaply in laptops.
You should be able to get an i5 or i7 dell in this price range too. I suggest the Studio XPS 16--as it comes with better graphics.