TheStreet.com posted an article last week that raised the question about VMware's market dominance, noting that the company's stock price took a hit (a 27% drop-off since November 1) while some of VMware's competitors questioned its hold on the market.

The article said that Goldman Sachs analyst Sarah Friar posed the question of whether VMware, the "big gorilla," has an unbreakable hold on the market.  To which, Edward Walsh, CEO of Virtual Iron said, "It's not a foregone conclusion that they're the gorilla forever."

And now that Citrix has acquired XenSource, they are making similar claims.  John Bara, VP of Marketing at XenSource said "Channel, scale and Microsoft are three things that are going to change this market."  And he added, "VMware's advantages are starting to erode" what with the latest reseller agreements Citrix made with HP and Dell and the fact that the desktop application delivery giant plans on selling XenSource virtualization into its already existing 200,000 customer base.

Read the article at TheStreet for more details, here.