Those of you who tune in with me each week on the Heroes front already know that Adrian Pasdar’s character, Nathan Petrilli, was recently written out of the show. There is now talk of other Heroes cast members moving on to bigger and better projects, including Sendhil Ramamurthy, who plays Mohinder Suresh on the show. NBC recently cast Ramamurthy in an upcoming comedy drama set to drop sometime in 2010. With many of the major characters slowly departing from the series, fans across the world are wondering if season four is the last season, and rightly so.

Speculation about the end of the series isn’t just circulating among fans, but has also been on the minds of the cast and crew, who seemingly have no idea what the future holds in store for Heroes.

Despite the fact that Heroes continues to pull in viewers and rank on the high side when it comes to ratings, the truth of the matter is that in comparison to season one viewership, which pulled in an average of 16 million viewers weekly, the show has lost more than half of its regular viewers. On the other hand, NBC’s ratings overall have dropped in the last year, making Heroes one of its higher rated series.

Why the drop in ratings? We could speculate that it’s because people are watching less television, but in hard economical times it tends to be that more are staying in, which should boost ratings. Maybe the ratings drop is on account of the content. Anyone who has been watching Heroes since the beginning can pinpoint the problems that have cropped up in recent episodes. The recycling of plot material from season to season has gotten a little predictable. I mean, really, you can only conflict with Sylar’s potential to be good so many times before it gets stale, and I’ve said myself a dozen times that if Hiro saves Charlie one more time, I’m gonna puke. With Nathan Petrilli dead (again?) and Mohinder Suresh preparing to take a dive, two of the series’ favorite characters are going to leave a major hole in the series.

While there has been no confirmation from the network that this is the end, viewers and critics agree that it’s only a matter of time. One can only hope it isn’t too late for Heroes to bow out gracefully, but as Hiro struggles to save Charlie again, my own outlook for a memorable ending is about as faded as that invisible girl from the Sullivan Brothers Carnival. Either way, I’ll be keeping my ear on the news for confirmation that season four is the end for our heroes.