Eh...my eye's really don't care. 720P looks just fine for them on my phone. And I don't really even watch videos on my phone. If I'm watching something that I actually care about, I'm doing it on my MacBook or my television. So this really doesn't concern me. I imagine others, who watch things often on their phones may be more bothered by this though.
I just don't find comfort in watching anything in depth on my cell phone. That's why I bought an iPad, MacBook and a TV.
720P is the most I ever use on my cellular iPhone or iPad anyway so this announcement only has good news for me: increase of 5GB on my mobile hotspots, from 10GB to 15GB, at no extra charge for those who switched to the new Unlimited since February. Great news!