mmo-champion/worldofraids are 2 of the most popular sources for this kind of news. I don't trust anything they say without blue until the PTR is up, but from that point on they're pretty reliable. _________________
11 Mill hp is a bit much, considering some of the highest Teron parses are maybe 38-39k raid dps, with totally staged groups (i.e. 3-4 healers max, 5 shamans typically). You've got two extraneous players because of a 3 tank requirement (maybe have 2 pally tanks if you can bubble off the debuff?), so the dps requirement is pretty ridiculous. However, that's what the PTR is for, and it's nice to see that things in Sunwell are probably going to get harder rather than easier.
You could probably go with a pally/warrior tank and two ferals. That'd likely produce the most DPS you could do without switching out. However, the amount of guilds that have that + all the DPS that could do enough for this fight is...small. We're talking a lot of buffing, even on non-progression content.