I think there are a couple of other Roomba affectionados out there in empegland... so I'll share this news here.

iRobot's intro-info page
http://www.irobot.com/sp.cfm?pageid=334

RoombaReview forum thread
http://www.roombareview.com/chat/viewtopic.php?t=6043

I'll be shipping back my 'broke-six-ways-from-Sunday' Discovery from 2004 to Hammacher Schlemmer as soon as they start stocking the new 570. Yay for full-refund guarantees!

BTW, I'm up to 7 Roombas.
Disco I - HammSchlem, broken down and used for parts
Disco SE - Amazon refurb, works fine, out on loan
Disco SE - craigslist, works fine, out on loan
Disco SE - craigslist, gone crazy
Gen I - free from friend, gone crazy: possible transmission failure
Gen I Pro - craigslist, brushes not turning
Red - craigslist, works fine

I must be nuts.