Not sure quite yet, but noticed on Nascar.com new updated web page under the Bud Shootout Practice Leaderboard and Cup Series Practice Leaderboard that scanner is listed as an option now.
I hope they've added this feature for 2009. I really think it would be better for fans to listen to the driver & crews communicate during practices also.
If you haven't ever listened to trackpass during a race, I can say it makes things alot more interesting. You can get a 14-day free trial to try it. I highly recommend trying it.
(CAUTION: WHILE LISTENING TO ROBBY GORDON YOU MIGHT BE EXPOSED TO UNCENSORED LANGUAGE)