1/2/07 - purchased prius
1/2/07 - went to BayArea FasTrak center with temp reg. and purchase contract with printed VIN# to get transponder
1/2/07 - dealer (SF Toyota) electronically registered and used available license plate in vault so I was able to get a plate number right away
1/3/07 - mailed DMV Clean Air Sticker app via USPS Express Mail for morning delivery 1/5/07
1/17/07 - $8 check shows cashed on my ebanking statement online.
1/18/07 - waiting nervously for stickers

When I purchased the Prius on 1/2, I estimated about 8-10 days of additional stickers available at the current application receive rate of about 200/day and about 2000 stickers left (after all pending apps were filled). So I think its pretty risky at this point to purchase. Probably better to look at used Prii that already have the sticker.

Thanks again to everyone who posted on this forum (and also priuschat.com)