Trolltech is an open source company by virtue of their dual-licensing of the QT tool kit that is used by a number of products but probably most notably the KDE desktop. Though they do dual license and sell commercial proprietary products as well.
The Nokia deal was reported in kroners (NOK) at 843 million making the purchase worth about $154.4 million in US dollars.
2006 revenue for TrollTech was 174.1 Million kroners or $38.8 million. I wish I could find final data for 2007 but as it stands the revenue for last quarter and 2006 and the first three quarters of 2007 Trolltech had revenues of 213.8 NOK.
Barring a blowout fourth quarter that makes the purchase price of Trolltech about 4 times revenue which is a much lower multiple than the recent MySQL, Xensource, and Zimbra acquisitions. Though it does validate the appetite proprietary companies have for open source.