So what do we need table locking for? You want me to fix it for you? Should I join the developers mailing list?
Ed,
we could definitely use your help on wikitech-l, there's a lot of optimizable SQL, some tables aren't indexed where they should be, the PHP code can probably also use some tweaking. Particularly high load operations are internal link resolution (see my recent wikitech-l mail) and orphaned pages listing (haven't tested the latter on the main Wikipedia because it took so long on my local install).
Regards,
Erik