Okay, so after a little consultation and break from yesterday's nonsense, here's the verdict. Discussing the wiki policy and specifically how and what jokes are acceptable is fair game. Go for it. I've attempted a sort-of-clearish split along those lines, but I probably ended up punting a few comments to the locked side. Rather than screwing around with more post splitting, people can re-post their thoughtful comments in this one.
To be absolutely clear: this discussion needs to be forward looking and about wiki content. Absolutely no slagging of past decisions, rubbing salt in current open wounds, or criticizing individuals, period. Any of that and the post gets punted to the locked thread and the offender gets a formal warning.
For what it's worth, my feelings are that a few harmless minor jokes in the wiki are a net positive, but we certainly don't want every wiki article to suddenly become littered with them. The rest of you who actually routinely contribute to the wiki can sort this out, however.