Switching to "next" branch

OK, so my GIT fu is weak. HOw do I switch to the “next” branch so that
I can pick up the
gr-uhd stuff.

Assuming that I have a current trunk spinning on my local disk, what do
I do?

You have won an RTFM!

http://ettus-apps.sourcerepo.com/redmine/ettus/projects/uhd/wiki#Gnuradio-UHD

-Josh