Saw this recently.
Nokia to acquire Trolltech
This BusinessWeek article about it (as well as some of the other Net sites that reported this news), says that the acquisition for $153 million.
Don't have much of an idea about the pros and cons of this acquisition, but the author of the BusinessWeek article above seems to think its a good move by Nokia.
Trolltech seems to be a good company - I had blogged about one of their main products, Qt, some time back, and had tried it out some. It's very good. Qt is considered by many to be a very good cross-platform GUI toolkit (for C++, now also has Java support via Jambi), and a good example of a well-designed object-oriented library. They also have another similar product for mobile devices, Qtopia, which was developed after, and based a lot upon, Qt, and Nokia is probably acquiring Trolltech because of both products and the synergy between them (because of the common codebase and probably similar API's, its likely that Qt apps can easily be ported to Qtopia and vice versa, which will make for cost savings and faster development time).
Some of the articles about this Nokia acquisition mention that Google Earth and the Skype client, among other products, are developed using Qt. I think I read somewhere that Adobe Photoshop is also developed using Qt.