The review below says that the 640x480 is taken advantage of at that full resolution due to some Windows Mobile 5 implementation.

http://www.mobiletechreview.com/Dell-Axim-X51v.htm

Perhaps the browser still feels more responsive than on the 770/800, but it's also wireless b, which limits range. Based on my recollection I don't get a full b-connection everywhere in my house.

So for me, the Axim is close to a competitor, but I still wouldn't call it competition. That Cowon Q5 looks like it will be the first one to really go the distance, and it will be strong competition since it's a full media player. Can't wait!!