This is actually a pretty big turning point for Apple's mobile division, not because of Force Touch, but because of RAM. We are already seeing a feature in iOS9 that will be exclusive to next generation devices with multitasking, and iOS10 will most likely see some UI elements exclusive to 2GB devices. Now that 2GB of RAM is needed for multitasking, I would be surprised if the 6s came with any less than 2GB.
The 6s will not necessarily be a huge upgrade over the 6 in the short term though. It is kind of a catch 22, but an upgrade from the 6 to the 6s would only be advantageous if you weren't planning on upgrading to the 7, as most of the benefits of the 6s will not be realized until late 2016.
Matt
I think Apple plans to sell the 6s for at least 2 or possibly 3 years so that extra gig of RAM will be critical to the marketability of this iPhone when it becomes Apple's 2nd tier phone in September 2016. I think the extra RAM is actually more beneficial in the long run for the 6s than the 64-bit A7 processor is for the 5s. If Apple releases a 6c this September and it also has 2GB of RAM, then we'll know Apple's intention to make sure all iPhones released in 2015 can take full advantage of iOS 9/10 and not be "unofficially left behind" like 1GB iOS devices.