Facebook is the wonderful new tool that allows you to obsessively check on what other "friends" are doing, who they are dating, where they went clubbing last Saturday night and how big is their brain.
It also allows you to share with these "friends" exactly what you are doing at the moment, what is on your mind and other existential matters that are bugging you.
But this tool can also be used to share information and arrange meetings and nights out.
Therefore, to facebookify is to keep someone informed via Facebook of everything that is going on in your world, that might (or might not) matter to them.
Guy #1's post on Guy #2's wall: Dude, I promised I'll facebookify you with an answer. So, he goes: yes!