Well the game will keep selling on PC I would hope, some people might pick it up after opting out after the state of the demo even if they liked the game. Holding onto the game though if you dont like it is only hurting the community unless you are making content for UT3, see it could be given or sold to someone who would actually play it. I think thats important here, you can bitch about the game all you want even after paying for it but its not going to do anything.
Id rather see people who enjoy the game taking it online and playing it, patch or not because I agree the patches arnt going to dramatically change the game. If you think they do or will then perhaps your reasons for not liking it in the first place are unfounded.
For the record, Ive played through UT99 and UT2004, I enjoy UT3 both off and online. I recognize its not perfect even irritating at times but Im not going to sit here and expect everything to be fixed over 1-2 months acouple of weeks of which is a holiday for most people. I think the patches specifically this one could bring more servers perhaps higher quality ones ran by people who know wtf they are doing and how to setup a match of UT, player counts for me arnt a huge issue. Ive joined empty servers and within 5 minutes Ive had 2/3 players to play against even more, heatray TDM seemed to draw the crowd

theres a DM server here which is 24/7 listed and almost always has humans playing in it. For a small country such as Australia UT3 aint going so bad, I rekon it'll just take some time for people to upgrade, purchase and get into UT3
Perhaps other countries are seeing dips in player counts because theyre more console orientated or have more dual gamers who opt for the console player counts, which only makes the situation worse btw.