All Skype really plans to open source is a Linux version of its client. The protocol remains proprietary. So if you have a Linux phone and want to support Skype's proprietary protocol on your new hardware, you can.
Yes, there's an open source version of Linux client being developed. This will be a part of larger offering, but we can't tell you much more about that right now. Having an open source UI will help us get adopted in the "multicultural" land of Linux distributions, as well as on other platforms and will speed up further development. We will update you once more details are available.
It's a half-cheer for open source.
All Skype really plans to open source is a Linux version of its client. The protocol remains proprietary. So if you have a Linux phone (Moblin, Android, etc.) and want to support Skype's proprietary protocol on your new hardware, you can.
This is the first technology move by Skype since eBay sold it to private investors for $2 billion , followed by assorted legal shenanigans. Everyone involved in that deal wants to protect that value.
But telephony is a low-bandwidth application. Its value going forward shouldn't be voice as-such, but the integration of voice with other computer applications. In that world being wholly proprietary is a disadvantage. But opening up completely may be seen as giving away the goose that lays golden eggs.
Skype is caught east of the rock and west of the hard place. It knows it needs an open source strategy, but it fears giving itself away.