How patient will Carl Icahn be with Genzyme's (NASDAQ:GENZ) turnaround plan? That's the $270 million question -- the value of Icahn's shares, based on his holdings at the end of the year.

Genzyme announced yesterday that the billionaire investor plans to nominate four people, including himself, to Genzyme's board. The move wasn't surprising, given the increase in Icahn's holdings at the end of the year, but you never really know with Icahn. On one hand, he's also waging a proxy battle with Biogen Idec (NASDAQ:BIIB), but on the other, he's said publically that he doesn't plan on going after Lions Gate (NYSE:LGF).

Exactly what Icahn plans to do with Genzyme, should he get four of the nine board seats, remains a mystery for now. It would be a lot easier to find a buyer for Genzyme than it is for Biogen, because Genzyme doesn't have Biogen's complex partnership deals. It would also be easier to get a bidding war going for Genzyme than for a company like Amylin Pharmaceuticals (NASDAQ:AMLN), where Icahn also has board representation. In Amylin's case, the most obvious buyer is its partner Eli Lilly (NYSE:LLY).

While Genzyme could probably find a buyer at a premium in the near future, it wouldn't command the value possible if the drug company executes its turnaround successfully. Perhaps Icahn's plan is a little more long-term like it was for ImClone Systems. There, he held the chairmanship for nearly two years before getting Bristol-Myers Squibb (NYSE:BMY) to bid on, and ultimately enticing Eli Lilly to purchase, the biotech.

Genzyme hasn't yet proposed its own list of nominees for shareholders to vote on, though they'll likely come from the current incumbents. The company has said, at least superficially, that it's willing to talk to Icahn about his plans. It's even possible that Genzyme and Icahn could strike a deal, perhaps by giving Icahn a seat or two, which would buy the company another year or so to get its act together. Genzyme made a somewhat similar deal with another large shareholder, Ralph Whitworth, to trade a board seat in exchange for support of the company's nominees.

Patience may be a virtue, but it's not the fastest way for activist investors to make a buck. Unfortunately, we'll all have to be patient and wait to see what Icahn's next move is.