As usual with goofy stories of this sort, some of the ideas are downright laughable. Jeff Bridges? Way too old. Joseph Gordon-Levitt? Too wimpy. James Franco? C'mon now.
One of Weiss' ideas hits the bullseye, though. Reading Dave McNary's story this morning, Seth Rogen's hirsute visage instantly came into focus. He's bankable, and he has a certain sweetness about him that the late Grateful Dead guitarist also projected. And yeah, he wears a beard well. Among the young stars of today, he's probably the best fit for the gig.
Rogen as Garcia: Far out, man.