I know many people that are not happy that Ubuntu One is a default package with Ubuntu; I am not one. I have found the service to be invaluable with the diverse machines I use in a week. With Lucid Lynx (Ubuntu 10.04) I noticed that there is a right click option on folders to sync the folder with Ubuntu One. I have not given this feature a try yet, but this feature could make it easier for me to use Ubuntu One. Check out the full image from the thumbnail below:
It will be interesting to see if and how this changes the Ubuntu One usage for most people.