tedster - 9:04 pm on Apr 5, 2011 (gmt 0)

The link Scott_Mc offered in the third post is to a recent official Google blog article that recommends a 301 for mobile users who request the desktop version - that includes the googlebot-mobile crawler.

The article is from Feb 2011 - I'd consider that to be the current official word on the type of redirect. The technical challenge (and gray area) is recognizing all the mobile user-agents properly.