As you know, Sinestro has been a Green Lantern since he was mysteriously chosen by a green ring in Green Lantern (Vol. 4) #67. Since then, he’s been the star of Green Lantern Vol. 5, and Geoff Johns has stated that Sinestro will remain so for the foreseeable future.
Aside from the obvious fact that I think it’s bullshit that Hal Jordan is dumped in the backseat of his own goddamned book (which he has been since 2007!), I don’t mind the concept of Sinestro returning to the Green Lantern Corps. Johns has done an excellent job of making Sinestro a much more interesting character over the past seven years, and seeing the arrogant villain thrust into a role he was once comfortable with but had grown to despise makes for some fantastic comics.
What I don’t like is that the “New 52″ reboot will likely be used as an excuse to whitewash or erase most of Sinestro’s evil deeds. Johns did the exact same thing with Hal in Green Lantern: Rebirth, and Hal’s “crimes” were a drop in the ocean compared to what Sinestro has done. Given Johns’ reliance on retcons, there’s a lot of precedent for throwing away Sinestro’s history.
Without doing so, the choice of Sinestro as a Green Lantern just doesn’t make sense. He’s not just a villain; he’s a supervillain. The man is quite literally responsible for the deaths of billions, not to mention the conquest of entire worlds, committing genocide, and the creation of an evil army. That just doesn’t fly with being a Green Lantern, no matter which continuity you may prefer.
So, in order for any of these recent stories to work, a lot of those past sins would have to be wiped clean. That MadGod Sector 3600 business? I doubt it ever happened. Even recent stuff, like “The Sinestro Corps War,” is likely to be dramatically altered. My guess is that it’ll be retconned as a small, localized conflict rather than the original intergalactic bloodbath (if it happened at all). I’d be surprised if we even get an explanation as to why a green ring chose Sinestro again!
I should also point out that Sinestro’s path to redemption undercuts the entire rationale for Green Lantern: Rebirth. Just like Sinestro, Hal was a hero before going rogue. Thus far in the current comics, Sinestro is having to work his way back up and redeem himself. Hal, on the other hand, was retconned into the perfect hero by having all of his foibles be the fault of a giant space bug. If Sinestro can redeem himself, why couldn’t Hal? Unless, of course, Sinestro’s legacy of villainy will be blamed on Parallax as well. That’ll make his sins that much easier to expunge, as nothing will be his fault anymore. Ugh.
But I digress. Rather than retcons, what kind of explanation for Sinestro’s return to the Green Lantern Corps would I prefer? Instead of Sinestro’s horrible crimes being erased, keep them in continuity…and have his current Green Lantern status be a forced penance. And as to why the ring chose him, and is stuck on his finger…that’s the work of the Guardians. They’re simply lying to the rest of the Corps about it, as they’ve done countless times before. Rings can no longer choose their wielders automatically due to Mogo’s destruction, and some intelligence clearly guided it to Sinestro’s hand. Why not the Guardians, in order to make Sinestro pay? While he’s stuck with the green ring, Sinestro wouldn’t be able to use any yellow rings, either. We’ve already seen that his own Corps has marked him for death, so if the Guardians are responsible, they’re punishing Sinestro and tearing apart his army in the same stroke.
This is all just wishful thinking. I’m worried that we’re setting ourselves up for disappointment if we expect any satisfying answers, or for something truly great to come out of Sinestro’s new role. Regardless, all we can do is wait.

Everytime Johns retcons soemthing, George Martin kills a Stark.
Now THAT is a great comparison! I think I need to put that in my message board signature. (I’ll credit you, of course.)
I’ve only read the first three books in A Song of Ice and Fire, but I love them. I’ll start book four after I clear out a little more of my backlog! And yes, I’ve watched the television adaptation. Can’t wait for season two!