Groovy isnt hip
With a kind of weird cryptic syntax, it reduces the lines of code by making code less readable. Didnt we learn our obscuring lesson with C? The beauty of languages like Python is not only the abstractness and easy of use, but also readability. Of course the creators of Groovy will rave about its virtues, and an ugly baby will always look beautiful to its mom, but this baby needs to be put to sleep.
Positive Note: I found Groovys flaws in a one-hour presentation, rather than several hours of playing around with the tool. A good reason to be at JavaOne.