Before we start I want to say that I am by no means very well versed in the Lore of World of Warcraft. I know enough to get by, but I'm no expert so I'm putting this together based on what I saw during the Demon Invasion Part 2.
Warning: In case you didn't read the title; SPOILERS
I'm going to skip over most of the interesting stuff that happens in Ulduar and get to the part that's interested me the most. We find out that the Planet itself is in fact a Titan. Pretty awesome stuff, but today I was clearing Ulduar as I do every reset and I was thinking;
"It's a tad weird that Algalon came here to re-originate the planet, that is itself a Titan..."
As I was leaving Algalons Chamber, I noticed Azeroth spinning on a pedestal. Along with 6 other Planets. 7 Planets in total. If Azeroth is a Titan, why couldn't these other planets also be Titans? What if when the Titans were defeated they were turned into Planets or something? So a quick Google and I find that there are in-fact, 7 Titans, including Sargeras.
What if the 7 Planets shown here in Ulduar are the Titans? What if our understanding of the Titans is completely wrong?! Albeit they were, or can take on some form of Avatar, but they're actually planets? The Burning Legion is taking over and destroying these planets in the hope of killing off the Titans?
Random thoughts, random ideas, might be totally wrong, but what do you think?