The previous episode threatened to be a comedic Halloween romp, and instead took a far better turn into season arc territory. To be honest, I was expecting more of the same in the episode, so I was a bit surprised to discover that there was another absurdly strange installment on the schedule. For the record, that makes three episodes out of the last four with strong comedic overtones.
This brings to mind two examples with two very different outcomes. The first example would be the fifth and final season of "Angel". That season began with a game-changing shift in status quo, a run of largely stand-alone episodes in the first half of the season, and a stunning and devastating arc in the second half. In other words, fans were nervous at first, but the season was ultimately rewarding. (Hopefully, "Supernatural" will avoid the fate of "Angel", which ended at least one season too early.)
The second example would be the sixth season of "The X-Files". That season began with a few plot-heavy episodes, and then ran with a string of "special" episodes and more light-hearted fare before returning to the plot for a sweeps event. Unfortunately, the second half of that season slipped back into more episodic territory, and many fans were left disappointed by the apparent lack of focus.
It's far too early to tell which way this season of "Supernatural" might go, and that leaves some fans nervous. I admit, this episode leaves me a bit concerned. But the best predictor of future behavior is past behavior, and in this case, we know that "Supernatural" has consistently delivered for three seasons, despite some casting difficulties. The writers have generally avoided the episodic/serialized divide that marred the "X-Files" run, and tend to pattern the pacing of season arcs in ways similar to the Joss Whedon model.
All of which is a long-winded way of saying that I will continue to keep the faith, even though this episode felt like something of a misfire for the season and Ben Edlund. There were certainly plenty of funny moments, but a lot of it just didn't hit on all cylinders. I think part of the problem was the disconnect between the previous episode and this one (Dean's admission at the end notwithstanding).
The story was also largely disconnected from the brothers themselves. I've found that the quality of an episode is proportional to how well the treatment of the "monster" or "legend" intersects with the character study. The best episodes tie the character angst into the tale directly. In this particular case, the Brothers Winchester only vaguely discussed what they might have wished; most of the impact of the wishing well was external to them.
The final product was, therefore, a pretty average episode. Amusing at times, certainly worth the effort to watch, but not on par with the best episodes of the season by any means. Granted, it seems odd to think that an average episode is something of a failure, but that's the thing with "Supernatural". It's usually so good that a bland episode stands out as a disappointment.