There isn't anything developers are going to come up with that needs more than 1GB. This is a phone, not a datacenter.
Absolutely NO developers are complaining about this limit.
Just get yourself ready for 1GB for the next 10 years. This is the upper limit of the use model in a phone, like how CPU speeds have stayed constant for the last 10 years, save for power reductions.
You're living too much in theory, not practice.
Remember, the goal of a smartphone is to do less, not to do more, because of power concerns. You leave the heavy compute to the desktop.
If Apple keeps the iPad with 1GB of RAM for the next ten years, that's all the more reason for me to stay the heck away from tablets. One application won't use 1GB of RAM, but iOS does sometimes have to free up RAM by closing apps or uncaching Safari pages, which is annoying.
By the way, there will be a point at which 1GB of RAM and 2GB of RAM will cost the same, or 2GB might even be cheaper.