First I heard about it the other day.
Apparently it's government-mandated chip in cellphones, some already have it, by which the goverment can overide other communication channels to send you a text message. Appears there are a few different levels of messages that you can block or opt out of, except the "Presidential Alert" messages from the top.
Wonder what else the special chip might do? Probably nothing they can't already do, just makes it easier to do it, what ever "it" is.