The new DOE rules, if implemented, won't go into effect until July, 2011. Who is selling DV now based on what's going to happen in July, 2010? The DOE is giving all education companies lots of time to fix their problems.
Since most investors are looking at 1 year expectations then yes they should care. But doing the math to go from 40% to 45% would mean they would need to cut enrollment by 10% to get rid of the weak. And that means less revenue and less costs. So, I predict they would show a modest 10% growth instead of 17-20%. Which would justify a forward PE of 10x. Which is about 43/share. But that is all just mumbo jumbo out of my head. A stock is only worth what someone is willing to pay or sell it at.