Today the KHL entry draft took place. The rules of the KHL draft could be found here http://en.khl.ru/news/2009/6/1/13673.html 
The list of drafted players http://en.khl.ru/news/2009/6/1/13671.html 
Viktor Hedman was drafted # 83 overall (of 91 picks) by the Spartak Moscow. So, if Hedman decide to play in KHL he could sign only with Spartak untill he turn 28 (if his right wouldn't be traded). Taking into account that Spartak is one of the poorest KHL clubs, I doubt that it could happen.
John Tavares went undrafted.