Another routine desktop upgrade.
Most of the big changes - ZFS, LXD, Ceph, seem to be mainly relevant to the server version. Even if you wanted to use ZFS for example on the desktop, you won't get it unless you reformat your drive. Few desktop users will bother, because quite frankly few will really care about it.
For desktop users, it looks like its mainly a series of incremental upgrades. I don't expect to really notice much difference other than that some apps will be at newer versions.
I expect that I'll upgrade my desktop some time tomorrow or the next day when I get a bit of spare time. It's generally pretty painless. There will be more desktop configuration options, but I doubt that I'll look at them. I can't be bothered to change much other than changing which icons are in the launcher (which should carry over from the current version) and the desktop wallpaper. I suspect that most other users are the same.
I know this doesn't make for exciting news, but I think that most desktop users aren't looking for excitement. They're looking for boring predictability with marginal improvements, and I expect 16.04 to deliver on that when it comes to the desktop.
People looking for excitement will need to look to the server, including the new IBM mainframe support.