Here's my prediction for fitness in the next decade. I think we're going to see a lot less machine-based, isolation type exercise and more of a movement towards functional training. Bodybuilding, with its emphasis on hypertrophy(muscle size) via isolation, has had a profound impact on fitness since the 1970s. In a sense, progress away from the isolation mindset is more of a regression to pre-1970s fitness.
    I have a lot of respect for bodybuilders-- they put a ton of dedication into what they do. But does it make sense for everyone else to train the way they do? And couldn't  they themselves benefit by supplementing their program with more functional movement patterns?
    By functional training I mean training that mimics as closely as possible movements related to everyday life or to sport. When in your day-to-day life has someone forced you to sit in your chair and extend your leg under load? I've definitely never seen it happen on a soccer field. The mechanics related to a leg extension (as in a kick) are far more multi-dimensional than occur during a machine leg extension-- in this case we're looking at balance, joint stability, and a different neuromuscular recruitment pattern!
   Now don't get me wrong, isolation type exercises and machines can have a place in your workout. I'm especially a fan when we're looking at a specific muscle imbalance. But in order to make the most of your workout, consider training other components of fitness along with muscle group strength. Train like you play!

--interesting note-- correct me if i'm wrong, but I believe it was one of the early bodybuilders that invented nautilus, one of the first exercise machines. I'm too lazy to do the research right now!