I guess you have not missed the news about Microsoft aquiring Skype. Although Microsoft told they will continue development on all versions of Skype I have my doubts - and so do others too.
Recently Digium, a company that develops an integration for Skype with Asterisk, had to give up because Skype/Microsoft is stopping the partnership - read here.
You are free with your own interpretations on this but I am already searching for a replacement for Skype.
The very sad thing these days is: As soon as a software got really good and really adds value and/or increases your productivity, it gets destroyed somehow - being prices getting too high or not being continued. This way we will never step out of the bronze age of IT...
What you can see here as an example: People often say that in Open Source world you don't have a guarantee that the software is supported and continued. As you see here, proprietary software is not different here. But in open source world there is always the option to fork (see OpenOffice->LibreOffice). This option is missing in proprietary world. So basically in Open Source world you are more safe!
Related post: The Open Source movement.