The cool kids won't move on to Scala for a number of reasons, the primary of which is that Scala's actors are not as powerful as Erlang processes.

See Virding's First Rule of Programming (http://www.nabble.com/Erlang-concurrency-to14747956.html):

"Any sufficiently complicated concurrent program in another language contains an ad hoc informally-specified bug-ridden slow implementation of half of Erlang."