Just take a look at those known to have signed nondisclosure agreements in exchange for access to Dell’s (DELL) data-room:

Lenovo (LNVGY): How on earth would the Chinese computer-maker pass U.S. regulatory muster? Sure it managed to get approval for its 2005 purchase IBM’s (IBM) personal computer unit, but that was long before the issue of Chinese computer hacking was a major part of America’s defense discourse. It also was before CFIUS blocked threatened to block Bain Capital and China’s Huawei Technologies’ proposed acquisition of 3Com. If CFIUS was uncomfortable with Chinese access to computer network equipment being used by U.S. government agencies, what about Chinese access to the actual computers?

Hewlett-Packard (HPQ): Meg Whitman theoretically could go all in here, and try to corner the frozen orange-juice PC market. But HP would have regulatory issues of its own (antitrust) and there is no indication that HP shareholders have the stomach for another massive acquisition. And then there would be the question of if Michael Dell would vote his shares toward having his namesake company taken over by a rival that mocked his acquisition announcement.

Carl Icahn: There have been rumors that Icahn floated a $15 per share buyout offer before asking for a special dividend (he’s since entered the go-shop process), and Dell’s special committee would like nothing more than a way to prove its not beholden to Michael Del’s offer. But take-private buyouts aren’t really Icahn’s stock in trade. Instead his agitation lately has been more around the margins — trying to force others to increase their own offers, thus increasing the value of Icahn’s minority holdings. He’s also acquired control stakes in some listed companies, but would Michael Dell stick around in such a situation (unlikely, given his animus toward the public markets)? And, if not, why does Icahn think public shareholders will view Dell as more valuable with a Michael-for-Carl trade at the top of the corporate food-chain? Remember, few people were talking about Dell as a $13 per share stock — let alone a $15 per share stock — before news of this buyout leaked.

The Blackstone Group (BX): This is the most likely of an unlikely bunch, given that (1) Michael Dell has indicated that he would work with a private equity firm other than Silver Lake, if it offered a higher price, and (2) There wouldn’t be any regulatory concerns. But Blackstone has a terrible record when it comes to large tech buyouts, which helps explain why many of the people who led those deals are no longer with the firm. Moreover, it’s hard to imagine that new hire David Johnson (i.e., Michael Dell’s former M&A guy) already has enough clout to push this one through investment committee (assuming that’s his aim, which is unknown to me).

It’s also worth noting that the financing for Icahn or Blackstone could prove tricky. Not the bank debt, but that $2 billion loan from Microsoft (MSFT).

My understanding is that the Microsoft money is specifically tied to Silver Lake’s involvement (old pals from Skype). This isn’t to say that Microsoft wouldn’t hitch its wagon to a rival bid — after all, its main prerogative is to protect its ecosystem — but the software giant is under no contractual obligation to do so.

To be sure, none of this means the $13.65 per share offer is destined to stand. Icahn’s pressure alone may force Michael Dell to bump up his price. But I’d expect the final shareholder vote will be on the Michael Dell/Silver Lake offer, whatever the specifics of that offer ultimately include.

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