The easy answer with Apple is always to wait when this close (three months) to an official announcement...
Then the real strain begins, If this is truly going to be a tic toc toc scenario, the 7 may not be a good upgrade choice over the 6s UNLESS there is a a standout feature for your use case. For me, the camera is a critical component - more so than voice call quality itself - so when the iPhone 6s Plus came out, I jumped from my year old 6 Plus, and switched to a one year upgradeable contract at AT&T (it was available before Apple announced their program). IF (the big if) the 7 Pro comes with 12mpxl dual lens cameras for optical zoom and stabilization, then I'm in for another upgrade. Otherwise, I may play out the hand until 2017 to see what real design innovation is all about.