You can access it at http://www.reddit.com/r/CatNet/ and if you are interested in this topic, please subscribe to it :)
To seed this community, I added my recent Cat.Net-related posts. and here is what it looks like:
For reference, here is the current introduction text (to be rewriten once there is more activity on this Reddit community)
"Since Microsoft stopped supporting its static analysis engine there is no place to talk and discuss about this engine and what can be done with it.
There is a lot of Cat.Net related activity happening (for example at the OWASP O2 Platform project), so the objective of this Community is to capture and enhance it"
I am a recent Redit user, but the more I used it the more I like it
... starting to think of creating a Reddi't community for the O2 Platform... :)