Fox didn’t surprise much of anyone when they announced the cancellation of Prison Break. The chief concern about the show was always its sustainability; that’s why Fox was initially reluctant to pick it up and why the producers considered doing it as a miniseries instead. Like Heroes and a number of other shows from the 2005-6 serial fad, this had a built-in “and then what?” problem — the premise is so front-loaded that once you get past all the initially-interesting stuff that the idea offers, there’s not a whole lot left to do.
Lost and 24, the most durable of the serialized shows, are durable in part because they do have a certain built-in sustainability. Lost is sustainable because, like The Fugitive, the premise can’t completely burn itself out until the producers are ready to give us a full-fledged ending; no matter how many arcs get wrapped up, we’re still kept waiting for the big finish. And 24 is sustainable because every season is really one very long self-contained episode; the show can reboot every year just by giving us a new terrorist plot for Jack to foil. So Lost is still about being stuck on an island, and 24 is still about a badass dude foiling terrorist plots, but Prison Break hasn’t really been about the Prison Break for quite some time.
The cancellation will leave this show, which once looked like a big hit, with only four seasons and about 75 episodes (because the third season was strike-shortened). That’s a pretty good run, but it’s always something of a disappointment because it’s not quite enough for a syndication sale. (Not that this matters so much to a serialized show like PB, since that kind of show has no future in syndication one way or the other.) A show with a four-season run is usually one that started out looking like a hit and then burned out, or got moved to an incompatible time slot, or something; they’re not quite flops, but they’re not quite the kind of show that manages to hang on for a five-year run either. They are shows that are almost hits but not quite.