[Will]

They never meant for it to be a long drawn out series, but for one with a definite beginning, middle, and end planned out. Granted, seasons two and three had a lot of mediocre exposition in it, and the series probably would have been better if it was a three-part series plus the intro miniseries. I don't think there was anything that could have been done to extend the story any farther, though. Unless you want even more mediocre crap filling in between the character development and main plot points.

Besides, after revealing four of the final five this past season, there ain't much they can do to top that. If that ain't jumping the shark, I don't know what is.