Gnome3 won't start after 13.1->Tumbleweed update

Hello openSUSE users!

I have used openSUSE for a couple of years and I was really exited when I was told there is a rolling release version of the OS. So I gave it a try on a brand new installation (x86_64), but I wasn't successful and ended up with a broken Gnome3 and a messed up system...

What I have done is to install 13.1 64bits Gnome version on my system (brand new install), update packages with yast online update, then follow the guidelines to get Tumbleweed. Neither proprietary drivers, nor virtual machine, nor spicy stuff. When I rebooted, what I only got was a "Oops, something went wrong" Gnome3 message and inability to connect to my session with GUI...

Analyzing the /var/log/messages told me that symbols were undefined in .so files:

As suggested in this thread (May 2014), I have checked the version of libgtk and I was surprised it was still 3.10, as well as some other gtk3 packages. The fact is when crawling the repository, libgtk 3.12 is available, but yast couldn't see it (repository priority?). So I tried to install the 3.12 gtk packages with zypper and rebooted. But the problem wasn't solved at all and I was still struggled with a broken Gnome3. When I analyzed the /var/log/messages again, the same g_app_info_monitor_get was missing.

Eventually, when I checked with yast, everything involving gtk3 was at 3.12.* version.

As suggested in the opensuse-gnome mailing list (May 2014), I have tried to use xdm instead of gdm, but it didn't help.

I don't know then where is the problem. So I have reinstalled a 13.1 version and run with it, but I want to try out Tumbleweed (with Gnome)! What could you advice me? Wait a bit longer?

Thanks for your answers!