Back in February, there was an interesting whitepaper published on MSDN regarding the performance of WCF in comparison to the previous technologies: ASMX, .NET Remoting, MSMQ, and Enterprise Services.  I just learned about it a few days ago.  It apparently took a month or so to start gaining momentum around the web.

Since this is a frequent topic of discussion for folks interested in adopting WCF, I thought I would pass along the link.  It is certainly a good read if you are curious about the topic.  I won't regurgitate all of the information here, but it essentially illustrates that WCF performance is superior to the previous technologies other than certain scenarios under Enterprise Services.  It did not get into P2P performance of WCF, but it would be highly dependent upon the configuration anyway.  (Hmm...sounds like something fun to do when I have a little time to kill.)

Here are the goods: http://msdn2.microsoft.com/en-us/library/bb310550.aspx

Enjoy!