Each and every one of you has affected my game play over the years. I too have times where I have trouble staying motivated to play UO. I know exactly what you mean Aedon, where logging in seems more like a chore and hindrance. To be honest, it was about 8-10 years or so ago that I began feeling that way. I was on the verge of quitting, but because I loved the game so much I thought of reasons to stay and it came down to the desire to achieve all game content that there was to complete and I did have fun for a while working on various projects, running guilds, going on various hunts and especially my return to the almighty PvP. To to be honest the PvP is the only thing left in the game for me that provides anything left that most resembles the thrill I used to get back in the day so these days I play for two reasons, the people and the pvp. I have been moving along (with periods of inactivity) ever since but I still find enjoyment in the game and this is still the best online game and it is still to a point "what we make out of it."
The flame for the most part has burnt out, but the few occasional times that you can cause a spark, and get a taste of the fun we had back in the day, make it worth it for me.