I had actually thought of waiting some more in view of what I've read about issues with WLAN connectivity, e.g. that one cannot access the N900 by ssh after it has been idle for some time or, more worrying, a significant reduction of WLAN connectivity itself. But not least because of this thread here I finally did it. Since I'm using vpnc from devel, I started by de-installing that, de-installed a couple of other packages, and then the OTA upgrade went very smoothly. After the reboot everything looked fine, except that I already knew that WLAN wouldn't work before I did
which was made necessary by vpnc having touched that file.

Next, a reboot to have everything in order. The fly-by boot video flew by, and then a blank screen. Not completely black, but almost. Like the screensaver having kicked in, without having made it to final darkness. But it couldn't be woken up.

Then I tried using the camera. Funny, the camera seemed to work. However, closing the camera brought me back to the previous state. Why did I do this not entirely necessary upgrade? I had been so happy with my N900, now it seemed gone...

However, pressing the power button for somewhat longer brought up the Nokia boot screen, and pressing some more, turned the phone off completely, after which it came to life at the next boot.

I've now tested the upgraded system only so much, but I'm pleased by what I see. It seems it is quite a bit smoother in every respect, also the portrait mode of the browser is a nice additon (after 4 failed attempts with ctrl-shift-o, which only brought up some file dialog). So except for this brief shock of one failed boot-up after the manual installation of the new libicd_network_ipv4.script, it seems I also had a problem-free PR1.1 update. So far, I haven't even seen the sshd to become inaccessible. If that happens only after a rather long time, it would actually be no issue at all for me - I could accept it even as a security enhancement.

I'm just curious now: has anybody seen his N900 in a similar coma-like state after the upgrade or after this manual intervention with libicd_network_ipv4.script?

Be that as it may, I'm happy now and above all very grateful to those who figured out how to handle the issue introduced by vpnc (for which I'm also grateful, because I need it for work, although this package clearly needs some maintainance.). Thanks, folks!!

UPDATE: Another scare on day 2 with PR1.1: all video clips and music files have disappeared. With the file manager I could see that they were still there, started a video clip successfully from the file manager, but when I tried the same with my music files, the file manager crashed. I tried a few more times - whenever I tried to scroll down my folder of mp3 files, the file manager stopped working and had to be closed. However, a reboot solved that problem. Now all my video and music files were again accessible by the media player, and also the file manager could handle them. I guess that tracker-processes had not been refreshed before my first access of video and music files and the subsequent reboot. So still no real problem with PR1.1 so far. Most imporantly, so far I have not encountered any of the problems that others have reported with WLAN connectivity.