Thanks to a user dump, we now have a Arnova 8G2 4gig stock ROM dump.
THIS IS NOT for the 8gig memory Arnova 8G2!!!! It is ONLY for the 4 gigabyte version.
I am taken the ROM apart and it looks good but I cannot test it to be sure.
This is update.img. If you are bricked from another ROM you MUST use the RKBatch tool whoch you can download here.
Here is a great post by ZonaMojo about how to flash with the RKBtach tool.
And finally here is the ROM download.
ROM -> Arnova 8G2 4GB model - Stock ROM update.img (75 megs)