Microsoft has decided to pour gasoline on its long-burning feud with VMware, with a full-page ad in USA Today meant to give customers pause before signing up for the latter's virtualization services. If you believe it's a coincidence that the ad appears just as the VMware-hosted VMworld kicks off in San Francisco, well, I have a bridge in Brooklyn to sell you. For cheap.

"VMware is asking many of you to sign three-year license agreements for your virtualization projects," reads the ad, ostensibly authored by Brad Anderson, vice president of Microsoft's Management and Security Division. "Signing up for a three-year virtualization commitment may lock you into a vendor that cannot provide you with the breadth of technology, flexibility or scale that you'll need to build a complete cloud computing environment."

Anderson then makes the pitch for Microsoft: "If you're evaluating a new licensing agreement with VMware, talk to us first. You'll have nothing to lose and plenty to gain."

This particular feud isn't new or low-profile; during July's Worldwide Partner Conference in Washington, D.C., Microsoft COO Kevin Turner described how his company would aggressively pursue VMware's key corporate clients. From the transcript of his keynote:

"In the next six months VMware, the majority of their enterprise license agreements will expire and require a renewal, because when those were formed three months ago we didn't really have a good competitive solution, but what a partner opportunity we can go after right now in the next six months."

During the same event, Microsoft CEO Steve Ballmer claimed the company held 30 percent of the virtualization market. Virtualization products play a key part in Microsoft's future plans, which also involve extending cloud-based IT services to the enterprise. And that's enough to get Microsoft rolling at the smaller company with the aggression of Marlon Brando heading for the buffet table. (Yes, I've used that line before. No, it never gets old.)

USA Today, of course, doubtlessly finds its way to the doorways of most hotel-rooms in the San Francisco area. I'm just wondering how many VMworld attendees will give that ad serious thought.