I have been upgrading my laptop from Ubuntu 8.04 to 10.04.
The process was fairly simple. My laptop is a Dell Inspiron 9400 and, because I need to ensure maximum uptime, I bought another hard drive (WD Scorpio 250GB WD2500BEKT) to install the new version on. I like to have an easy bail-out strategy for these things and $NZ100-ish is a small price to pay for peace of mind. So I did not run the upgrade script on my existing setup, I installed from clean. This is a good thing to do from time to time anyway because rubbish does accumulate (stuff I thought I would use etc that is too much trouble to hunt down and remove).
How did it go? Very smoothly. After doing the main install I installed everything I needed using the package manager and that was almost all I needed to do. I had to install oracle XE from a separate download and I had a problem on my second monitor. The monitor display was 'wobbly', I could just about read it but certainly not well enough for it to be useful. Googling showed other people were struggling with this problem but the answer was from this guy. Very simple and it worked right away.
I had some minor issues with getting CVSNT working properly after I copied my local repository over but that was just a case of following the instructions closely and doing what they said.
Thunderbird files copied over just fine and set up all my folders and calendars etc. Firefox didn't but I used the export/import for that and it worked.
Things I have not yet verified:
1) Do the VirtualBox machines still see my USB ports? I had issues with that earlier and the answer was to use the non-open version of VirtualBox. No problem, but I'm not sure which version I installed this time.
2) I haven't yet installed my 3G modem. I rarely use it directly, I normally plug it into my wireless router and wireless is working just fine.
3) Phone sync. MyPhoneExplorer, which is a Windows program, was a pain to install on Linux earlier and it never has worked that well under Linux. It is very nice under Windows but when it runs under Wine on Linux enough extra features are crippled for me to look elsewhere for a simple sync program.
But my Java development environment works, email works, open office works etc etc. So I am all set. Now back to Madura Rules development.