So can the Reds' hot streak last? Well, we can use a team's Pythagorean record as an indication of how closely their record matches their performance--which then can indicate how they can reasonably be expected to perform in the future. The Reds are currently rated as one game BETTER than their Pythagorean Record, whereas they were five games under Pythag when Narron left. That means they're roughly 6 games over Pythag under MacKanin...which, if we do the thought experiment, drops his managerial record with the Reds from 29-19 (0.604) down to 23-25 (0.480).
A 0.480 team is certainly a heck of a lot better than what we had before, and is closer to how most of us expected the Reds to play this season (I predicted a 0.500 year in the Hardball Times Preview). Unfortunately, this also indicates that it's probably rather unlikely that the Reds can continue to play 0.600 ball for the rest of the season, so we may be disappointed if we start to allow ourselves a bit of hope.
These data also probably indicate that while MacKanin has done a good job with the Reds, the turnaround in performance probably hasn't been as dramatic as the record indicates. So no, I'm not really on the "Hire Pete" bandwagon right now.