I don't think Microsoft would want to pull the plug on Skype for Linux. Its in their best interest that it work on as many platforms as possible, I think. Even if they did, something else would just come along anyway. I remember when AOL purchased ICQ and basically drove it into the ground. At that time ICQ was the number one IM thing, but now its probably one of the least used. That just shows what can happen when a huge company buys something.