Thumbnails are so 2008.
In a portfolio site, thumbnails are just another impediment between a prospective client and your work (if I read this correctly). And with broadband speeds going up, I think thumbnails are more cost-controlling measures on the business side than usability on the client side. With these 700px shots, it’s pretty clear what my site looks like without going to it.
As for the perspective warp? I just thought it was neat.