There are sometimes broken packages, but never anything important and you won't notice - apart from the fact that apt-get complains occasionally. Plus, any bugs that do occur are fixed within the day.
It does mean a lot of updating, though - there are at least 10 packages upgraded every day. Oh, and when I dist-upgraded, apt-get decided to uninstall KDE and install Gnome again, much to my disappointment.
So it's not a big deal to wait; the main reason people are upgrading is to try out Compiz anyway, but boy is that fun
Steve