I would look at the dell web site to see what they are offering. What am I using? I bought this case a couple of weeks ago, and it's working out really well:http://www.targus.com/ca/product_details.asp?sku=TLF405
I know this one is for 15.4", but there was one for 17" at Staples.
I like the relaxed look. I looked at alot of cases, and Targus has really good padding (on the sides, and specially on the bottom where you put the case down). While most others seems to be lacking in this area as the padding is alot thinner.