I have upgraded my system to Ubuntu 10.10 Maverick Meerkat. So it's the end for Lucid on my machine. Quite a time to express my thought on it.
Probably the most stable release of all I used. I can note only a couple of problems I had. First, I had few cases when system didn't boot when machine is turned on, hopefully it did after first hard reboot in all cases. I think this is related to Plymouth, though I'm not sure. Second is the X server, which somehow moved to other virtual terminal somehow. I needed to press Ctrl+Alt+F8 to get it (I remember one case, when I needed even F9). In all cases this happenned when system was at GDM login screen waiting for someone to log in. Everything else worked really well.
Mostly it worked well. There were few cases, when Totem YouTube plugin didn't work, but I think this was due to changes in YouTube itself, as in all cases this problem went away after system updates. Another disappointing thing was that Epiphany plugin HTML5Tube didn't work at all. I don't remember any other issues, so I proudly say that this is the best Ubuntu release I've used.
I'm now using Ubuntu 10.10 for 2 days, maybe let's wait about 2 weeks for first feelings about it :)