"There is a lot written in fine print and you have to go to Microsoft and quote chapter and verse from the user rights section of the EA," says Muscarella. "If you don't do that, or don't know where to find those EA clauses, Microsoft is happy to charge you for everything you do."

It's not clear yet how Microsoft will fit Skype into its enterprise product line or its enterprise agreements. Muscarella predicts that Skype will continue to be free for consumers and small businesses, but warns enterprises that Skype may be snuck into a suddenly more expensive CAL, even if it's a dollar here and a dollar there.

"If you have a lot of desktops - 500 or 1,000 or more - the license costs will add up quickly."

Despite the mainstream attention the acquisition received and Skype's popularity with consumers, it still ends up being just another technology that Microsoft can roll into an EA to potentially impose added or unnecessary charges on a business.

"It's potentially a license gotcha like anything else," says Muscarella."You have to make sure you are not forced into a one size fits all model and fight with Microsoft to whittle the EA down to what you need."