I am going to cover both sides of the aisle here.
I agree with many, it simply is too early to tell what this system is going to turn into. We won't know for sure until Disney starts making details public.
Until then, there are basically two main theories:
1) We get FP+, and only 3 FP's per day. In my book, that would be total suckage, and would lead to horrible wait times in standby lines, though those lines would likely move faster since there wouldn't be the constant flow of people entering from the FP line getting priority.
2) The new FP+ system integrates with the current system. You can choose the times of 3 attractions ahead of time, and change those times as you see fit. The remainder of your passes, you get what ever time is available, and they work like the current system, where you can draw only one at a time, and not get your next for two hours, or until the start of the return window for your current pass. This system would work fine for me, and is what I am hoping that FP+ turns into.
Only time will tell what we really get though!