EDIT: Nevermind. This has extreme potential to be crap for the reasons others have suggested. In that case it would only be a mass pacifier.
There are a few things about this announcement that I like, and maybe one or two things to note.
This only works gmail to gmail, and the text will be decrypted at either end. If your computer is compromised, all the messages to and from you will be compromised as well.
Google has committed to making it available and easy, which is pretty cool, and they are releasing the code for study prior to release for use. That is very cool. I can only hope that the code is good, and that it will ALWAYS be open for inspection by anyone at any time.
"We recognize that this sort of encryption will probably only be used for
very sensitive messages or by those who need added protection. But we
hope that the End-to-End extension will make it quicker and easier for
people to get that extra layer of security should they need it."
Hopefully everyone will use it all the time for everything.
There are risks, and Google has helpfully pointed out some of the potential problems for us here.
Looking forward to see where this goes.