The main reason to upgrade to the (not so) new fedora release, was that i wanted the desktop eye candy that comes with compiz and beryl. On fedora core 5 i was forced to use the vesa display driver, but fedora core 6 had a much newer i810 display driver which should detect the i945GM graphics chipset on my D620.
After some googling around i decided to do the whole upgrade process through yum via the network and that proved to be surprisingly easy.