Three of our best and brightest gave a talk last night on H2O, R, Scala and Hadoop (yes -all together and yes highlighting the integration).
If you missed the talk last night the slides are linked here, and we're doing an encore next week (http://www.meetup.com/SF-Scala/events/153854762/ )
Tom Kraljevic presents using H2O on Hadoop – how we've integrated and what we've learned
Michal Malohlava presents the inner magic of Scala in H2O
Anqi Fu presents integration with H2O and R