Looks awesome, but there are a few things that i would add.
A compare checkbox you can use to compare items, I would also like to see the compare feature in a similar manner to the demo you have showed us.
A quick specs button. You have it right now in the search, why not include it. I know you can look at the pic and then View Details. But it would be nicer if it would pop up and give a little about itself when you hover over it for a few seconds or something like that.
This is a really nice setup, it works fast and smooth. Only problem i see is getting everyone to download and install silverlight.
EDIT:
For those that like linux, they have a version out that will let silverlight work with linux called Moonlight
Just go to the demo page and find your way to the download. Still working on getting a working version for ubuntu. Will post back if i get it to work. You need silverlight 2.0 to use the demo newegg made.
EDIT EDIT:
the moonlight 2.0 is still in pre-Alpha stages for Linux. So I give up.