If you want to know my opinion of sending the two guinea pigs straight into their first Cata zone --Vashj'ir-- I think the title pretty much sums it up.
For those of you who were around on WoW prior to Cata*, can you remember what it was like taking your first toon at ~L55 and making a mad dash for Light's Hope Chapel? The Eastern Plaguelands was the scary zone in the Old World (sorry, Silithus and Blasted Lands), where it seemed the waves of Scourge were unending and you had to go at a crawl to reach the one safe place in the entire zone. Oh, and it sucked if you happened to be on the road at the same time as the Scarlet Courier; you'd have been better off just running into Plaguewood naked instead.
Of course, all things being equal, some toons were more equal than others at dealing with the challenges of the old Eastern Plaguelands. Paladins were custom made for the zone, while Cloth wearing toons suffered the most.
In a very real sense, that's what I felt when Neve and Tom swam out into Vashj'ir for the first time.
Neve, as a Frost Mage, has the built in advantage of a minion.
Boy, did she need it.
My experience leveling with her in the Old World (pre-v4.0.1) came in handy. The mantra "nice and slow" was vital to her survival. She could handle one 30-40k HP enemy at a time, but two made her sweat. She had very little recourse for healing during a battle, so she had to rely heavily on damage mitigation using her shields. Because the Naga were a) all over the place and b) prone to aggroing on her, she was forced to stand and fight a lot. The shields she had were often exhausted before their cooldown was over, so these fights became a DPS race. Afterward, the Conjured Mana Strudel was steady part of her diet.
Still, she didn't die at all until the "defend the ship" event.
A Cloth wearer like a mage is often a sitting duck in a melee style event, and Neve was no exception. She survived multiple attacks by one Naga, but two at once were almost too much. And three...
After that experience, things became a little easier. She finally started to get a few Cata greens, and her health (and firepower) jumped 3k. In fact, the only time she died after that was when the rare Lady Ya-Ya (yeah, I know, a nod to Lady Gaga) spawned right behind her.
Tomakan, by comparison, has built in healing, and is surrounded by nice, hefty (if puny by Cata standards) Plate. And when Art of War procs, Exorcism will deal 10k damage at a pop. He found the going quite a bit easier than Neve did, and he didn't die once. Okay, I don't think the elite giant catching you from behind should count, but that's just me. I did follow the same rules that I laid down with Neve: one enemy at a time, switch out damage (Ret Aura) for protection (Protection Aura), and go slow. I'll admit I was a bit concerned that Tom would have it harder than Neve because she could get more damage in from distance than he could, but he made up for it in better armor protection and higher spiky damage.
Now, I think both toons are getting their Cata legs under them, and while they aren't going to be knocking on the door of any instances soon, I'm more confident in their ability to survive in the Cata zones.
So the question I posed, "can you survive in the Cata zones going straight from Northrend after dinging L80?", is so far a yes. Now, the "will you die a lot?" question is still out there, but we'll see. A corollary to all this, "how long will it take you to be instance ready?", now that's a head scratcher. I suspect it'll be after all of Vashj'ir is complete, but I don't know for certain. Even with the Cata greens I have, I don't have a high enough iLevel to get into normal Trial of the Champion on either toon, so that gives you a feel on how far I have to go.
*Okay, that's just about everyone, but you never know.