I hope I'm wrong (because wireless power would be cool), but after ~5-10 hours of research, I think wireless charging is unlikely to happen at any scale that would make UBeam a good investment.
The amount of sound power required to charge even small electronic devices is enormous relative to the volume of the sounds we hear every day. Therefore, charging must occur at a pretty high frequency that we can't hear. Power efficiency begins to drop at these high frequencies, however, and sound at these frequencies might have other unintended consequences beyond human hearing. Power transmission efficiency is low pretty much regardless.
The only way for UBeam to work, I think, is for people to think it's so cool to wirelessly charge things that they'll pay a lot of money to try it out. "Killing the power cord" on any sort of larger scale seems very unlikely.