I tried OS2007 on N770 too and I am seriously impressed.

It works and gave new life to my N770. So far everything I use (browser, media player, internet radio applet, osso-xterm) works fine. Even the browser (still old opera) has newer (IMO much better) interface and networking/browsing seems to be a bit faster to me. My webmail took long time from login to inbox in OS2006 (probably due to lot of redirects) but is as quick with OS2007 as on my N800 :-)

And what is also nice - you can dualboot between OS2006 and 2007 to have best of both worlds. Of course until OS2007 is better supported by applications because then OS2006 will be obsolete.

BTW if you have latest OS2006 and bootmenu installed you can just extract rootfs.jffs2 from FIASCO image and flash just this and do not lose bootmenu.

Yes OS2007 on N770 is unsupported but what does support mean exactly in this case? Are your favourite OS2006 bugs fixed? :-)