Sinestro is not only my favorite DC villain but one of my favorite comic book characters overall. I wouldn't mind seeing Mark Strong again, I'll probably keep saying that until there is a recast...he was my favorite part of the 2011 film.
It would be also interesting to have Sinestro BE the Green Lantern of the film instead of Hal, John, Guy, or Kyle (or Jade or Simon). HAIL SINESTRO!