Very volatile, all depends on his owner's faith that Koren will keep his nose clean. If you believe in him, you can't possibly trade him right now, as he's got proven top 20 upside. However, if you think he will slip up again, a great sell high moment is coming after he signs his deal.
Either way, it makes no sense to trade Koren right now. it makes a ton of sense to trade FOR Koren, with the assumption that you believe he has turned the corner on his personal issues. I do.
I just traded for him last week.I received Koren and a 3.02 rookie pick for Doug Jolley (the other guy, in a TE-required league, **only** had Eric Johnson at TE) and a 2.10 rookie pick.
I felt I could take a flier at a low-risk/high-reward type of WR like Koren and Jolley was my 4th TE.
If it doesn't work, I won't feel like I lost much.