The most obvious flaw with this concept is loss of efficiency. While it may be useful for small applications, it's ridiculous to think it would be wise for anything large scale where efficiency matters. Take the charging the car example. Someone charging their electric car wirelessly would consume up to 2 times the power to do the same charge as someone who plugs it in. The global energy crisis is serious enough without this extra measure of inefficiency.
However, this may be an acceptable alternative for small scale devices, but those too might have better options, such as simply attaching a high efficiency solar cell. There are also the various side effects of creating these resonating magnetic fields to consider. It sounds cool but probably just isn't practical.
