Now you can - by moving the mouse over the view bidder in the list bids area, it shows details such as:
When they registered
Feedback rating
What they have bid on
How many auctions they have bid on with this seller
How many bids they have made on auctions listed by this seller
If you click on details, it will even show how much time is left when they typically bid.
etc
http://offer.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewBids&item=220042252118
AM