This is a real positive. My cell phone, my GPS and my in-car DAB radio all power from USB - I can charge and use them all with just one lead, instead of having a glovebox full of a Spaghetti Junction of different cables and connectors.
It also means that when one charger goes wrong, it's insanely cheap and easy to swap it out for a new one rather than having to look around for often expensive manufacturer-specific accessories.
I regularly charge my phone with my Kindle charger and vice versa (and they even both use microUSB, so I can use the same wire too).