Skype IM and Internet telephony is, as far as I'm concerned, almost a core component of Windows Phone, which is why I've been complaining recently about its poor performance in terms of handling group instant messages. We last covered Skype mid-December, for the previously reported on v2.13 and today sees the release of an update, v18.104.22.168 - and Skype IMs do seem faster and more reliable. Comments welcome if you notice any other changes.
The official update changelog simply says 'General fixes and improvements' - but, given the existing state of Skype on Windows Phone all mobile OS, we'll take general fixes and improvements any day. IMs, especially with multiple contacts, had always been slow and unreliable and I'm hopefully that the 'All About' virtual office in particular will become easier to keep on contact with while on the move.
The Windows Phone Skype app can be downloaded from the Windows Phone Store.
For general information on future (and more major) updates, please also see the Skype Blog.