The basic idea behind the speed increase is the same as with newer USB chargers, which can feed a higher voltage to your device, pushing about 14 watts of power instead of the traditional 5 watts. Freescale has developed new hardware that can push 15 watts of power wirelessly. The downside is that right now, it requires new hardware in both your smartphone and charging pad; so, you can't just get this going. And, Freescale's chips aren't Qi standard compliant, though Freescale says that Qi compatibility only requires a "tweak", as would compatibility with lesser-used standards like that of the Power Matters Alliance.
Of course, it should be noted that the Qi standard does actually support up to 120 watt charging, if the hardware can handle it. Freescale says that it will have chips and reference designs ready for Q1 2015; so, it seems likely that we'll be seeing fast wireless charging hardware sooner rather than later.