Okey dokey, so this post contains spoilers for The Mandalorian, which I have not seen! But of which I know that
Luke Skywalker shows up at the end of season two there to pick Grogu up.
Whatever that means!
And so I'm really enjoying WandaVision, and there's supposed to be such a moment coming up, a cameo by, somebody CG Mark Hamill-esque, maybe in episode 5! So I'm getting my guesses in now.
1. My first thought when I heard there would be a surprise star cameo was that it would be... Tom Cruise or something! Playing Agnes's husband Ralph whom we haven't seen yet. Why Tom Cruise specifically? Because this mysterious Ralph is actually the demon Mephisto, and Tom Cruise would do wonderfully to play Satan??
2. It's supposed to be specifically more of a Luke Skywalker-style cameo, which means somebody we know but who's unexpected here. We haven't seen The Leader since the 2008 Incredible Hulk movie! It's gotta be Tim Blake Nelson, hasn't it?
3. Seeing how Skywalker was a CG Mark Hamill, Disney(+) are going to reuse the exact same assets and feature... Bucky Barnes, as portrayed by CG Sebastian Stan! Because Mark Hamill and Sebastian Stan look exactly alike! And they can just... or they can just (4) use the real Sebastian Stan!
5? It's gonna be CG Stan Lee, isn't it? Or maybe he filmed a cameo or two for the upcoming television shows before his death? (???)
So that is my thought.
POST-EPISODE FIVE EDIT: Okay, so I kinda saw that coming..., but I didn't see... *that,* coming.