The company I work for tried incorporating Groovy into several of our projects, but we started getting random permgen JVM crashes as a result. I believe this is due to the large number of classes it creates behind the scenes. This left a bad taste in peoples' mouths and unfortunately groovy will now be a hard sell.

Edit: Yes, we increased the permgen size and whatnot, but the outages it caused just left people with an unfavorable view of groovy. Which, as I said, is unfortunate, because I think it's pretty cool.