I have this afternoon installed Lubuntu 14.04 daily version from live usb.
No problems with the installation which was faultless from start to finish but on reboot I had an empty desktop; no panel; no menu, of course; just the background colour (black).
Right clicking on the desktop gave me the option to open the menu, thank goodness, as I knew it should from previous use of lxde and lubuntu, and from there I could set the session preferences etc etc, so now all is great, with everything as I want and the system running incredibly speedily.
I use a separate /home partition and used that for the new install, having come from Xubuntu 12.04, which was also great, but I am wondering if some of the configuration folders and files in my home from that previous Xubuntu install may have caused my difficulty.
I have not yet had time to search out the configuration files in detail to see if some of those pointed to applications and autostart of apps that no longer are installed, but I just wonder if anyone else has had a similar problem when installing, particularly when using en existing /home from another DE.
Nevertheless very well done to the devs of Lubuntu 14.04; it is already incredibly polished and once set up has been running with no problems for several hours.
Gret job ! ! !