Updated:
Here is the better audio version

And here is a sample of the media frenzy the track has generated
Revolver magazine
Blabbermouth
Metal Insider
Metal Sucks
The PRP

Still no news on what the unidentified and possibly new song Faith No More delivered as the second track of their encore in Buenos Aires last night.
Here’s a smattering of lyrics from the song – and two videos are below:
(I have a terrible ear for lyrics so please post amends and what you’ve gathered below)

We’ll walk the shore…????

We will rise from the killing floor / Like a matador

Let your sweet dreams never stale??fairytale/ Fairytales
We will be where you will be no more/ No more

The stain you bless, the hangman’s axe will serve you well???
Now we’re coming back/ Our time could waste all these???
We’ll jump the gates and ….?? We’ve arrived

We will rise from the killing floor / Like a matador

The killing, the killing

Better video version  -(via Nick in comments)

Fan video (loud)

Recorded from TV (quiet)