The idea of having 1 GIANT server is amazing but is that the truth or is it going to be smoke and mirrors? The amount of RAM a server is going to need to hold maybe what 500k+ players ,(at the minimum at my guess), is just unfathomable unless they have secretly jumped about 100 times better then current tech.

That's one of many things they'll be testing for in CB. I literally have no idea if this can even be pulled off, but they have confidence enough to talk highly about it in interviews and such, so we'll see.

AFAIK 2TB is the absolute limit on RAM currently, for a server O/S. That's a lot of friggin RAM.

People on the megaservers (there are two, one for EU and one for the US) will be split into instances, depending on preferences they selected and so on. It won't be every single person on the megaserver appearing on screen at once when you log into a zone - and there'll likely be caps for each instance. No idea if the instance we get on will be an instance of an entire server (my guess but who knows) or if they'll be formed each time we change area/zone eg walking into a dungeon/adventure zone, if those things even have any kind of area barrier at all.

They indicated it will be possible for us to get to know the players in our instance over time (assuming we don't change preferences I guess), so guessing the instances will effectively become our version of a server, except we can switch freely (so they'll be very dynamic).

It's possible the server runs on the same principle as a cloud, except in this case every channel on the Mega server is actually a different server and the main server is the control center