A correction: the guide uses PostgreSQL 7.2.3. I tried to go with stability over bleeding edge. Search 0.2 seems to work adequately and there were a bunch of issues with 0.3.x.
Once I've nailed down all of the remaining details (automated testing, best way to deploy code and content separately), I'll produce a new version for 4.6. And then I'll get to add a section on upgrading :).