I think the series might have one more good season left in it. 10 is a nice round number. With filming on ep 20 currently underway a cancellation this year would leave me feeling very cold as a viewer. I know I haven't been around as long as most of the community members but I have a sense of loyalty to the series and I really do love the characters with the exception of Blake who is just kind of there. Even if CBS only ordered up a short season for next year that would allow for a proper conclusion. it's not the kind of show that can truly wrap up since the events it portrays are creepily ongoing. There will always be crazies out there making the world unsafe. But with proper notice the characters could move on in a plausible way. If Shemar wanted out for example he might be willing to settle for recurring to allow viewers to say good-bye to Morgan. I personally wouldn't miss him all that much. I think Shemar is a pleasure to look at but I don't find Derek a huge contributor most of the time. He's smart but tptb often fail to make his contributions meaningful. Writer's fatigue combined with the fact that shows like this need 'the muscle' Not everyone can be the braniac. I think Derek departing would be most keenly felt in terms of character interaction with Garcia and Reid. Again, an important part of the show but something that could be written around or even used as a device to make those characters grow. The loss of any major character at this point should signal the beginning of the end. CM can go out in style. I just don't think is quite the right time to bid it adieu.