There are a few user group-like communities I am aware of
Bay Area Scala Enthusiasts, Silicon Valley Java Users Group,Bay Area Functional Programmers Unfortunately they frequently meet somewhere on the peninsula which is a decisive no-go for people working in SF and commuting on BART.Luckily, the latest Bay Area Scala Enthusiasts meeting was held at Twitter HQ in downtown SF yesterday. Naturally, I could not resist the temptation of walking 0.8 mile. The people were very nice and it felt so good to be in a true geek crowd. It would be great to attend such gatherings on a permanent basis so I am crossing my fingers hoping that the organizers will pay more attention to San Francisco.
The official presentation was a rather lame discussion of a nascent coding guideline. I would say that this is a non-issue (at least in the scope they mentioned) usually addressed by each team (e.g. questions such as "2-space v 4-space v tab formatting"). The fact that some people come to Scala from fairly uncommon scripting backgrounds complicated the discussion. Later the conversation shifted to real life experiences and favorite tools and that part was more instructive.
It was mentioned that in contrast to Java the question of Scala style is open because different approaches are used in Scala standard library. Many people are disappointed to discover that behind the functional API there is a lot of imperative code. In other words, although Scala seems to be the front runner in Java 2.0 race there is very little infrastructure (both conceptual - such as books/idioms/style guidelines and concrete - such as DI containers) in place or even under active development. And it looks like there is still enough confusion whether to re-use/wrap Java components or re-implement them from scratch.
Actually, I am surprised to find out that non-Java folks are interested in Scala. Judging from blogs web-heads are into dynamic /scripting languages such as Ruby. I believe Scala should be more appealing to people who moved to Java from C++ or find Erlang too weird because of its OOP-unfriendly nature.