Talk about irony. Watchers of the instant-messaging business have been lamenting the lack of real interoperability between the major-player systems -- namely, Microsoft's (NASDAQ:MSFT) MSN Messenger, Time Warner's (NYSE:TWX) AOL Instant Messenger, and Yahoo! (NASDAQ:YAHOO) Messenger -- for years. In short, users of the different systems couldn't truly "talk" to each other across company lines, requiring them to sign up for multiple services for best results.

This has been the case for ages, but the big players have never really taken meaningful steps to partner. Yet yesterday, we had Microsoft "coming around" in a press release, citing a Forrester analyst's recent comment that (in Microsoft's words):

... [I]nterest in IM for business use -- or enterprise IM (EIM) -- is running high. But many potential buyers are scaling back or postponing their planned investment as they run into one core question: Where's the return on investment? Without interoperability between networks -- including both public and private IM networks -- firms can only build half-baked versions of the high-value apps that will deliver the best ROI for EIM.

Well, gosh -- really? Really. The irony, of course, is that Microsoft was just timing its change of heart to coincide with another opportunity to make money. The meat of yesterday's release is the news that organizations using instant-messaging solutions can use Microsoft's Live Communications Server 2005 product -- scheduled for release in Q4, with pricing and licensing information to come soon -- to provide interoperable, secure, multiparty online communications.

This is surely good news for enterprise users. Heck, they were already sold on the value of EIM, so what's a bit more dough to make it a bit more useful? Tellingly, however, Microsoft's release says nothing of the consumer versions, which are still free to use. A Washington Post story, meanwhile, notes that "the three companies have no plans to permit users outside the workplace to communicate with one another over different instant message systems."

Maybe someday. On the other hand, maybe not: What years ago was little more than a hopeful customer acquisition tool targeting consumers has matured, perhaps unexpectedly, into a potential driver of high-margin corporate revenue. I'd be surprised if the "big three" had this written into the play, say, five years ago, but it seems to be working out just fine anyway. There's little prodding the powers that be to make a change; quite the opposite, it seems.

Fool contributor Dave Marino-Nachison doesn't own any companies in this story.