I was initially excited about it, too, for the obvious reasons rather than the meaningful ones. But then, the 'meh' plot of this movie (and the recent disappointing discovery of Toy Story 3's not-so-awesome-plot) kinda dragged me down, and like a rollercoaster coming to a stop, so is my adrenaline level.
I think everyone's gonna be so self-aware that it'll probably ruin all plausibility. Especially the scene with Arnie, Bruce Willis and Sly. It'll probably just be a load of tongue-in-cheek injokes. And Jet Li and Jason Statham will probably just do lots of silent glaring as they stand to one side.
What else has Stallone directed? We need comparisonisations!