In addition to the licensing risks there's significant technical risk, IME. Chief among them is making sure your colleagues are sufficiently literate to have read Bloch's and Goetz's (et al.) books, and sufficiently tasteful to synthesize those lessons into code which isn't horrible. This is exceedingly rare in practice. So there's the same risk, approximately, as with every other programming language and that's reckless Dunning-Kruger ass programmers.