Just last week, I was detailing Carl Icahn's canny move on Dynegy (NYSE: DYN). On Friday, we learned about Carl's next potential target.

In a "13D" filing -- signifying an active shareholder stake -- Icahn disclosed a 5.8% stake in natural gas producer Chesapeake Energy (NYSE: CHK), with a recent flurry of buying in the $22.72 to $22.89 range. Here's the disclosure from the section entitled Purpose of Transaction: "The Reporting Persons acquired the Shares in the belief that the Shares were undervalued. The Reporting Persons have had and intend to seek to continue to have conversations with the Issuer's management to discuss the business and operations of the Issuer and the maximization of shareholder value."

Other than the increase in his stake, none of this is really news. Back in August, Bloomberg quoted Chesapeake CEO Aubrey McClendon as saying that Icahn "told us he thought we had great assets, great management and were undervalued."

In response to this filing, investors have bid the stock up above $25 per share. Basically, folks are speculating that now that Icahn has amassed a considerable stake, he'll start pushing for some sort of value-unlocking event. That's not a terrible assumption, given his track record with past targets like Motorola and Yahoo! That, and the fact that he's accumulated a portion of his stake using margin borrowing.

Funny. You'd think that after McClendon's experience with buying Chesapeake shares on margin, others might refrain from the risky strategy. Then again, Chesapeake trades at less than half of its mid-2008 highs, and the shares are almost certainly a better value today.

Anyway, it seems pretty likely that Icahn will be looking for some sort of change at Chesapeake, though I have no idea what form that might take. If he is indeed happy with management, then it's hard to see what ideas he might have that Chesapeake itself hasn't already come up with. Between their volumetric production payment deals, joint venture transactions, and midstream IPO, you can hardly accuse the company of inaction on the financial tinkering front.

A management-led buyout, akin to what's been proposed at EXCO Resources (NYSE: XCO), seems far-fetched. In case you haven't noticed, the private equity industry has dialed way back on the size of its targets since the financial crisis. According to peHUB, the biggest deal of 2010 was the proposed buyout of Del Monte Foods (NYSE: DLM) for $5.3 billion. Chesapeake's enterprise value is over five times in size.

If Icahn thinks that company should be broken up or sold to a major like Chevron (NYSE: CVX), well, I don't expect management to be receptive. At all. This is co-founder McClendon's vehicle, and I don't expect him to hand over the keys without a fight. If this is the avenue Icahn pursues, expect big-time fireworks.