I just did an upgrade from 7.04 Feisty to 7.10 Gutsy (32-bit) on an older PC without a hitch (was running Fedora Core 5, then Feisty, now Gutsy). I did run into the refresh rates reportedly incorrectly by NVIDIA's restricted drivers, but disabling it in my xorg.conf (added line: Option "DynamicTwinView" "false") worked fine. Specs of the PC that worked great with the upgrade:

Mobo: Gigabyte GA-8IPE1000G 478 socket, Intel 865PE chipset, ATX w/ a 1.5 year old BIOS version
CPU: Intel Celeron D 330 (2.66 GHz socket 478 )
Memory: OCZ Platinum 1GB dual-channel kit DDR-400
Video: BFG NVIDIA 6600GT 128MB AGP (stock firmware version)
Sound: (using built-in sound)
TV Tuner: Hauppauge PVR-500 MCE
HDD: Western Digital RE 250GB SATA

Another success.