I think it's a great idea, obviously. If I had my way, Sprint Cup, Nationwide, and Camping World Truck wouldn't have any oval races. The appeal of oval racing, to me, is the pure speed of it, but obviously, Indy is faster on ovals, and the really fast ovals (Daytona and Talladega, which are so fast you need an FIA Platinum license to run on them, hence Brian Vickers is a Platinum-rated driver at Le Mans...bizarre, I know) require restrictor plates to make the cars slower, eliminating the speed element from it.
Meanwhile, the appeal of stock car racing, to me, is the ability to make contact and therefore take big chances. But with the aerodynamics playing a huge role on big ovals, you can't do that anymore. Only on road courses where, in a stock car, the aero doesn't matter as much because these cars don't turn anyway.
I think NASCAR's biggest reasons not to do it:
1. They don't want to compete with themselves. There would be people, like me or you, who would probably watch a lot more of the road racing series than the main one. Likewise, NASCAR likes to schedule companion weekends, where all the series race at the same track. Scheduling a road course series would be a nightmare, because it would have to be racing on opposite ends of the country to not detract from race-goers for the other events.
Solution: Run it in warm climates (Florida, Texas, California) during the off-season.
2. NASCAR owns Grand-Am, which sanctions the Rolex Sports Car Series, the Continental Tire Series (which they call "stock cars" and in a pure sense, they are, in a bizarre way), and the North American Ferrari Challenge. They also wanted to sanction an American DTM in 2013 but it's never going to happen. So they do have plans in road racing, but I think they want to keep it differentiated from NASCAR's main series.
Solution: Sell Grand-Am to Dr. Don Panoz who can merge it into ALMS.
At present, the trend is away from road courses. The NASCAR Canadian Tire Series runs just 5 road courses now. The NASCAR Toyota Series in Mexico has become a predominantly oval series as well (their major road course is an oval with a chicane in it

), even at tracks like Hermanos Rodríguez (the former F1 course) and Miguel E. Abed (WTCC raced there) that have both ovals and road courses.
Then there's the NASCAR Euro Racecar Series, which runs almost exclusively on road courses, but for three races on the same oval in Tours. They run some interesting tracks, and I even recognize Javier Villa from GP2 and James Winslow from Atlantics...
http://hometracks.na....com/races/EURO
http://www.racecarse...r-teams-gb.html
SparkNotes: I like the idea a lot, but don't think NASCAR would bite.