I don't really see why MS bought Skype at all. They already have the MSN service, which can do video and audio chat. And IM of course. So what are their intentions here? Do they want to convert all the Win/Mac/Lin skype users over to MSN? In which case they'd better provide a common platform.

Or maybe the other way around? MSN + Skype will move towards the Skype platform.

Either way it needs to be unified platform which will support Windows, Mac, Linux, Android, WinMobile ... OK basically every desktop and mobile operating system. Then it can become great. However if they fail to make it a completely unified messaging platform, then it will fall by the wayside.

I speak as a Linux Skype user, who pays to use the SkypeOut service to call landlines and mobiles around the world. Of course I will leap to any other platform which allows me to do the same, if things start to look dodgy.