Fairphone 2 Is the World’s First Modular Smartphone

I was wondering about Android updates :

"The Fairphone 2 will come pre-installed with Android™ 5.1 Lollipop. We provide a two-year warranty period for software maintenance. We plan to offer regular software updates, however, there are too many factors at play to give you a concrete schedule at this point."

2 years is short for a phone that you're supposed to keep a long time.

I'm seduced by the modular hardware but as long as they don't tell me they'll port the latest Android until the hardware can't run it, I'm not interested.