So there is a new Ubuntu and today I tried a dist-upgrade and succeeded (reasonably well). Here's my opinion on the new Ubuntu after the first few hours of actual usage.
First of all, I had the luminous idea of clicking my way trough the GUI-based update. NEVER do this, it tends to fail :) It did for me too, it chocked on a conflict between an installed and a maintainers config file. After waiting for quite some time, I decided to take the risk, cancel the process and do a commandline dist-upgrade.
To be honest, I don't like it much yet. I do like the Gnome-do alike quick launcher, but the global menu's annoy me a great deal. The new dock is not perfectly responsive and it is not movable. It is on the left and it stays there. Programs also seem to have lost the ability to put an icon in the system tray. This broke my nagstamon notifications for instance. The work around, provided here, works okayish. Still I am left with a floating notification bar covering half of the Ubuntu logo in the top left.
[update: It seems you actually can have applications in the system tray, you 'just' have to whitelist them. See here for more detail]
Another effect of the global menu's is the inability to add applets to the top bar. I used to run system resource usage information there, this can no longer be realised. All in all I guess I'll get used, or revert back to Gnome, but for now I am a sad panda.
There are a number of changes with lesser impact. Banshee was appointed the OS's new default music player. I haven't used it because I am a heavy Spotify user, but it looks a lot like Rhythmbox and it'll probably play music just fine. OpenOffice was ditched for the project that was forked off it: Libre Office. This seems a good thing, OpenOffice isn't exactly Oracles new pet-child and LibreOffice showed improvements on their first release.
Another change can be found in the Software Centre of Ubuntu. I hardly ever use it, but is extended with functionality to rate and review applications. Finally Natty gives applications the option to use a very small scrollbar.
While I am absolutely not sure if I like every solution, Natty succeeded in doing just what it was designed for: have as much space for applications as possible!