As for the ubiquity of Like, the new buttons will probably look like a Like button, and probably use an icon from the Facebook interface. That should help people make the connection to Facebook.
More buttons higher pageloads because not many sites use the 2-click versions yet.
Maybe someone should rethink the overall share model and find a new way to do it. Over time there will be more and more buttons all over the place.
Its good for improving page loads because you dont have to wait for 3rd party servers and also its an improvment for user privacy because your site is not automatically sending content informations into the graphs of all these sites just because someone opens a webpage.
I can only link to one project i know of, but its in german only atm http://www.heise.de/extras/socialshareprivacy/ another example would be techcrunch but as far as i can tell they only use it to improve the overall pageload experience.
I don't mean to point fingers, but I don't think this sort of thing is going to get any better: http://i.imgur.com/VeUr1.png