I think Don's point about the difficulty / confusion that accompanies any name change should not be understated. With that in mind I like keeping the OACS and changing the official A to Architecture. I also like the idea of changing pronounciation to "oaks". We could have an evolving icon of the state of "oacs" and an animated gif story ... the new release would be a seedling and as time goes on the tree/icon could grow with each release. The seedling could have started as a seed/branch that dropped off our neighbor "AD" tree. In addition when people ask didn't it used to be Arsdigita we could have an inside joke and make the A stand for different things (unofficially) ie ... this month its Asskicking next month may be Alchemistic.
All fun aside I think that naming this version 1.0 may represent problems. Ever try to sell 1.0 to mgmt or any potential client. Lots of coders as well steer clear of any 1.x release. Although if we do name the release x.0 coders understand that it is new branch so may have problems. I propose making the version 5.0 bypassing 4 altogether. Considering the dramatic changes in code and way things work compared to 3.x I don't think this is a big deal. The code has a lot of history and maturity even if it is a x.0 release. In addition we could use the Roman V and make 5.0 release stand for victory.
Also as time goes by we could even bring Alex back into logo as it grows ;)
