Plasma 6 landed in opensuse. However, I recommend to do it in tty because if you do it in plasma the upgrade will be incomplete because the shell will crash in the middle of update without installing all. In case this happen to anyone, just reinstall plasma 6 pattern and it will go without problems
I just installed this accidentally by clicking update all in the Discover app. It seems like it was successful and didn't fail halfway, but I'm still confirming that. Everything seems to be working as of now.
Yeah, when I saw the update I canceled, logged out and ran zypper dup from a tty. Rebooted and logged into a Plasma 6/Wayland session. Went swimmingly.
I think this kind of update is where "atomics"/immutables really shine. Install the update on a new separate snapshot and activate it at boot.
First logout of Plasma, then you can change to tty 4 (for example) with ctrl + alt + F4, then you can login there with your user and do the upgrade safely in that other tty (or another one if you want to haha, just not in the normal desktop).
I think the Plasma desktop is always in tty 3 (ctrl + alt + F3) and the Plasma login is in tty2, in case you want to go back.
In my case I had another WM installed (iceWM, I think it was there by default?) and did the upgrade from there. Unfortunately it does seem that if you try to upgrade from within KDE it will crash part-way (I used zypper dup and it failed).
Upgraded this morning. Everything seems mostly OK, but the login screen theme is odd, but fully functional. The lock screen is the same as before, though.