.Mechs will be on the decline but they will still sell due to aesthetics. That Skeleton Key mod looks mighty beautiful, not sure how it performs though. I've sold all of my mechs (all 4 types of Stingrays, SS/Blackhawk Panzer, Pegasus, Nemesis) except for my custom copper Panzer.
I actually think the 26650 hype will die out. Right now there's not a large amount of good lookers in the 26650 department and for the reasons that you would want a 26650 (primarily battery life), you would be better off using a dual 18650 box mod which would supply more power and charge faster since you can charge both of the batteries in a short amount of time whereas a 26650 will take quite a while to charge.