Hmm I just noticed the G8 version for O2 was posted here:
http://androidforums.com/samsung-i7500/9663-firmware-versions-2.html#post56326
So you could use odin to go to I5 - technically voiding your waranty - and if you ever needed to go back to a valid O2 build you could use odin with that file. They would never know that you had updated unofficially.
If NPS ever started working, you could just odin back to the G8 build and update from there. Previously there was no CSC for O2 so there was no way back to an official O2 build, but with this file we now have one.
Having said that the rapidshare link is dead, so maybe someone could re-upload it.