Ok, just noticed that mys tuff got indexed from the feed.
The admin at froogle sent me an e-mail to check that my site's feed has been indexed. He said to use "store:<storename>" to check and it works. All descriptions are fresh and not like on the site (no the titles as seen by Googlebot), but from the feed.
I can't differentiate between orders from froogle and orders from any other referer, but I'm getting a few dozen hits a day from them. I'd have to assume, based on overall site stats and sales, that at least a few have converted to sales - probably even more likely since people are looking to buy things from the git-go rather than general traffic you see from Google.