I've just switched to Ubuntu 10.10 from Jolicloud 1.0 and I'm very impressed so far! Only thing I'm not too sure about is Oneconf. I've installed it from the Software Centre and under File / Inventory on Ubuntu One both boxes are checked and I'm signed in. But how do I know it's working? And how would I resync my installed programs to a fresh installation? Next to "Share this computer's inventory" it says "unknown" even though the box is checked. Thanks
OneConf is still in testing, that's why it isn't installed by default yet. According to this blueprint, default inclusion has been delayed to Natty.
The current implementation doesn't actually offer much that you can do with the information that it stores in your account. For Natty, it's likely that we'll see integration with the installer. So that you will be able to include the packages on one machine when installing on another or doing a fresh install.
This wiki page has a lot of information with what you can do with the command line client,