Yesterday there was a new German whitepaper called "Second Life and business in virtual worlds" released done by Pixelpark AG and Elephant Seven AG.
The content is split in roughly three parts: first an introduction about what SL is, some things about the economics and three strategies how a RW company could make its in world presence, what to expect and what not, the advantages and weaknesses of the system, and how to be succesful with an in world campagne, how to get experience and so on.
The second part consists of many case studies, like Adidas and so on, what companies wanted to do in here and how they achieved it - or failed to do it.
The third part lists other 3d world projects, lists their attributes, advantages and disadvantages compared to Second Life.
For short: the target audience of this whitepaper is a project leader who must decide on if to get into SL or not. It tries to be a somewhat unbiased view of the things and of course is more objective than something from Lindenlabs or the main stream press, so it's worth a read.