I've built a b2evo machine running 1.9.2 in its stock configuration (including the DB schema).
As Martin says here there are many differences between our current codebase and the current 1.9.2 version, and I think it is too dangerous to consider creating a patch to upgrade.
What I'm implementing now:
With the new install I will incorporate Martin's patches one by one, ensuring that the app still works after each change. The first patch will be the DB changes that he made, then I work on the php. Once we're convinced that an upgrade will work I'll redeploy the new codebase on lettuce and set up a virtual host (like blogs.hcmc.uvic.ca).