I did the upgrade last night, having put it off for a few months. I the event, it went very smoothly, and so quickly that my router did not spot the loss of the HDA and take over DHCP (it was probably 10 minutes for the entire process, and much less for the loss of DNS and DHCP).
I did not bother to uninstall any apps, although I did not have many:
- HDA Troubleshooting Tools
Network Time
Disk Wizard
Web Apps
RPM Fusion (Non-Free)
Logitech Media Server
Webmin
IPsec VPN
proFTPd
The only one that did not make it was Logitech Media Server, which I uninstalled and reinstalled and is now working perfectly. The LMS issue was the CPAN issue mentioned in the Wiki, but CPAN was not found when I tried to run it, so I decided that reinstalling was the simplest option.