The markets are buzzing today on the rumor (here and here, for example), that either IBM or Cisco might try to buy Citrix. Of course the world is full of rumors, but there's at least anecdotal evidence that people are listening to this one as Citrix's stock moved up about 7% today, which is the biggest single-day move they've had in a while. (Although half-way through the day the stock has dropped about half that new value.)
Personally I would love to see a company like Cisco buy Citrix. (I've written about this a few times over the years, as far back as November 2005.) The short version of the story is that Cisco, as a networking company, is clawing their way up the networking stack to the more value-add stuff. But you can only take "networking" so far before you get into the "application" space. (Cisco's application-oriented networking shows some of their thinking, although that's largely around web apps.)
Of course the business world runs on Windows apps today, and that is Citrix's space. And Citrix can do amazing things when they combine SSL-VPN + Windows apps. (Read the "Smart Access" section of this article.) And Citrix will inevitably be able to do amazing with WAN acceleration + Windows apps. And then there's the whole NetScaler thing. And the XenServer thing. Actually, why wouldn't Cisco want Citrix?
As for IBM buying Citrix? Um, I'm less excited about that. To me, IBM is where good companies go to die.