Here's a quick summary, from the Language Design FAQ:
Go is an attempt to combine the ease of programming of an interpreted, dynamically typed language with the efficiency and safety of a statically typed, compiled language. It also aims to be modern, with support for networked and multicore computing. Finally, it is intended to be fast: it should take at most a few seconds to build a large executable on a single computer. To meet these goals required addressing a number of linguistic issues: an expressive but lightweight type system; concurrency and garbage collection; rigid dependency specification; and so on. These cannot be addressed well by libraries or tools; a new language was called for.
It's interesting that they are concerned with compilation speed, as modern compilers seem extraordinarily fast to me: I can build the entire Derby system soup-to-nuts in barely 2 minutes on a 5-year-old computer, and that includes building the entire enormous test suite as well as constructing the sample database.
They seem to spend most of their time comparing Go to C and C++; perhaps it's less compelling to somebody coming from a Java background?
Regardless, it definitely looks like it's worth learning more about.
And it's interesting that they are doing this using an open-source methodology.