Being a Java programmer, I don\'t really have a Groovy background, but I use Groovy a lot lately to extend Maven (using GMaven). So far, I could use all the Java code I need
There's a page on the Groovy site which documents some of the differences, and another page which lists gotchas (such as the newline thing)
There are other things as well, one example being that Groovy doesn't support the do...while looping construct
do...while