True, they've been to NYC before, but now it's Whedon the A-Lister writing, so everything he does will be treated as original...even when it's not. I mean, it's not like no one ever wrote a "X-Men fight a piece of their tech that gains sentience and wants to kill them" story before, or even an "X-Men go to space and fight aliens" story before. Hell, those two are X-CLICHES. But when you're an A-List writer, your FARTS get praise. That's not to knock Whedon, that is simply the nature of the biz. Once you go A-List, your good stories, your mediocre stories, and your garbage stories get a lot of hype and instant praise from the media insiders.
Hopefully Whedon brings more to RUNAWAYS than he does for ASTONISHING X-MEN, which has been riding on "mediocre, generic story but Whedon writes the characters well" ever since about CURE, and his pacing is slow as molassas to boot. I don't care who he is; BKV was a master and this was his creation, and Whedon will have huge boots to fill. Huge.
Maybe Whedon's going to finally tackle the mysterious Alex Debacle. Given his "experience" (and I use the word in it's loosest since. . . EVER) with undead characters. I really want a "Zombie/Undead/Stuck in Limbo/Shouldn't be alive" princling trying to create a kingdom in his own image while trying to win the heart of Nico. . . by killing Karolina.
Oh, well, yeah, Whedon will resurrect Alex. BKV made it technically possible and Whedon, like most writers, likely can't help stripmining his own past material. Expect Alex within 12 issues...if not 6. He's a self admitted RUNAWAYS fanboy, so expect fan-fic esque plots for better or worse.
What seperates "fan fic" quality with other stories? Easy; most fan fics are written from the heart, acting as self indulging wish fulfillment for the fan writing it. I know because I have written fan fiction. Other professional writers are emotionally invested but not so much that they can't shatter the status quo and do bold things, for better or worse. Both approaches have their pro's and con's. I just hope Whedon avoids a "Mary Sue" character with his RUNAWAYS new recruit.