Well, after I updated my scratchbox environment to latest Fremantle SDK I no longer see display updated inside Xephyr window. Only when switching to/from fullscreen display is updated. This happens to all maemo 5 apps (browser, control panel,...) in FREMANTLE_X86 target, not just scummvm. Previous SDK had only wrong colours :-) This is my old ubuntu 6.04 virtual machine I have since OS2006 days and I do all OS2006/7/8/Fremantle development there. I need to migrate it to something newer but currently don't have disk space for another virtual machine

That's why I have put is aside for the moment since the developer device should arrive any time soon (3 weeks since I ordered)

But anyway, the 1.0.0 scummvm release is out and the 1.0.0 source includes N900 fixes mentioned in this thread so it should in theory build out of box.

Then there is submission to extras-devel->extras-testing->extras and voting which can take some time too.

So to make it short - I was waiting for the device to do some final touches and already expected to have it. Look like it can still take long so I guess I can build Maemo5 deb and put it somewhere even without doing proper testing with real device.