So the install procedure was totally smooth - actually pretty boring.
First thing to notice was that MacFUSE wasn't working and therefore I had no access to my NTFS partitions and drives.
I tried to reinstall MacFUSE and the NTFS-3G driver. But that didn't help.
Next thing I did was to uninstall the NTFS-3G driver. Now I didn't get the error message every time OS X booted. I also uninstalled MacFUSE and then I was able to mount the NTFS drives (both BOOTCAMP and external USB drives) in read only mode. That is a start.
It seems that OSXFUSE will be around soon - and that could be the solution.
I'll keep you updated on this issue.
Next thing to notice was that the three finger gesture for switching back and forth in Google Chromes browser now did not work anymore (in safari it was changed to a two finger gesture). The three finger gesture switched between spaces instead it seems. Here there were an easy fix. Go to "System Preferences" > "Trackpad" > "More Gestures" and change the "Swipe between pages" from two to three fingers. That disables the new three finger gesture functionality but instead you can change that to a four finger gesture. I don't use spaces or the dashboard so disabling it will be just fine for me.
Next thing that was different (and not in a good way) was my "Hot Corners" configuration. I had configured it so that when I moved the mouse to the top-left screen corner i would see all the running applications. Now I get the "Mission Control" view instead. It is not that different from what I had so I will just have to get used to that.
There are also a few new applications in the dock - but other than that it seems to be business as usual seen from my perspective.