Best effort Oracle maintenance is what has and will be done FOR NOW, but I am almost sure people trying to upgrade now their Oracle installation will face issues.
Dear Andrew, we of course understand the reasons you raised for using Oracle, but be aware that this kind of support community has provided is fragile and has had almost no testing whatsoever, so if your company plans to enjoy new development on OpenACS you should seriously consider coding or other forms of contributions.
Something I think I can suggest to people using Oracle around is trying a fresh install of current OpenACS and give feedbacks, or even better go for an upgrade in a safe environment and report issues. Somebody could offer him/herself to address them.
Anyway, at risk of repeating myself, without concrete contribution from Oracle userbase all of you will eventually be left alone.