I'm not sure about kernel builts, Id just rebuild kernel and drivers with
new gcc. You don't have to do this, there is patch somewhere for vdr which
allows to use old gcc 2.95 but 3.4 might work better.
The last time I tested gcc/g++ 3.4, VDR built fine. But, you may run
into problems with building specific plugins with that version of
gcc/g++ (they are not all 3.4 compatible). IMHO, gcc/g++ 3.3 is a safer
choice. I also noticed that when VDR was built with 3.4, it tended to
use more cpu than when it was built with 3.3. There are alot of other
applications that are just not 3.4 friendly as well, like vlc for example.