Well, that was a bit of a surprise...
Talk about unexpected though. I would have expected Microsoft to simply port the dedicated supernode software to run on Windows and then deploy Windows servers for the purpose.
You'd think, but then again, maybe the software functioned so well already they decided to not put in the dev time for porting, and instead tweak what was already built.
To go with the car analogy, why build a [car brand A] when you've got a perfectly good [car brand B] in the garage?
Meanwhile, the Linux version of the Skype client is at 2.2 beta
Windows version: 5.9
Mac version: 5.7
Admittedly, this was going on before
Microsoft bought them, and I keep hoping Ballmer lives up to his promises
.... not holding my breath.