They're basically guardians and watchers, not the source of whatever power they hold. Malygos was not the source and center of magic. He was a dragon that was given incredible magic power and tasked with watching over that part of the world. Malygos dying doesn't mean there's no magic, it just means the Titan-assigned warden of magic is no longer warding it.
If Alexstrasza dies, everything won't die with her due to her being the aspect of life. If Deathwing dies, Azeroth won't disintegrate.
The Aspects were made to observe and protect. If anything were to come along and threaten the Titans' creations, it was their job to deal with it. It was also their job to make sure the evolution of the Titans' creations was going as planned. As we've learned in Wrath of the Lich King, there are a lot of threats and nothing is going as planned.
When the aspects stop protecting and start harming/destroying, it's time to put them down. It's like unplugging a security camera that's started to shoot laser beams at passing citizens.
"Question on authenticators - are they region specific? I play on EU servers but now live in the US, so would I need to order one from the EU Blizzard store, or would the US one work fine?"
I am almost entirely confident they are not region specific. The authenticators are all made by Vasco and, unless I'm mistaken, are shipped out of the US no matter where you're ordering them from. It would be a bit strange if they were region-locked.
"Question: Is it me or do elemental shaman have extremely low dps compared to every other class?"
Without any additional information to go on such as level of content, your gear, or any of that... I'll say no, they don't have extremely low DPS. Their DPS certainly isn't on par with rogues, mages, et cetera, but it's not extremely low. If you think you might be running into some problems on your end, you could probably link your Armory in the comments and get some good feedback if you're willing.
Michael wales asked...
"If the classic zones are changing for everyone, what happens to those of us who are still leveling in those zones? Will our entire quest line change, will NPCs just be moved slightly so they aren't standing in the middle of a lava pit? Are we just screwed out of the early story lines and we'll magically be a level 60-70 working on WotLK content (which I don't have yet either)?"
Yes, everything will change around you, just like what happens when they do content patches. If you were still questing in Icecrown when they patched in the Argent Tournament, those terrain changes happened no matter what. The terrain will still change, whatever quest chains Blizzard decides to redo in Cataclysm will change.
You won't magically be level 60 or 70, no. They're not getting rid of old Azeroth, they're revamping and rebuilding it. From a story standpoint, if you're a level 19 questing in The Barrens when the Cataclysm happens... well, the world explodes around your level 19 butt, and now you're dealing with the fallout of the Cataclysm instead of slaughtering zhevras for their nonexistent hooves.
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