Grzegorz Kossakowski will speak about the Scala+GWT project and how Scala reduces the amount of boilerplate needed compared to a vanilla Java GWT environment. You'll also see the Scala2JS compiler in action as well as a few live examples. Grzegorz currently interns at Typesafe and works on his master thesis at EPFL.
If you have any particular area of Scala+GWT interesting (eg. the Scala2JS compiler), please post a comment so Grzegorz can include that in the talk or put more focus on it.
We're looking forward to seeing you at the meetup.