Great extension though it would've been even better if you could actually "choose" which categories to regroup in tab. For example there are categories I wouldn't want to be tabbed at all (ex: the announcements) and some categories that would be great to tab with others, make a separation, and tab new ones. It'd add more flexibility and would prove very useful to many people in my opinion.
I totally agree, if it would be possible to have some forums without being grouped (shown through all tabs) and others to be grouped, this would be 100% perfect. Having just a tab for news can mislead people and make them not really check that tab what-so-ever sadly.