If you watched the Golden Globes last night you would have seen that award-winner Robert Downey Jr showed up for the event with some very familiar facial hair – the particularly defined goatee of Mr. Tony Stark. If you look back at the December junket for Sherlock Holmes, Downey was clean shaven – this is something he grew out over the holidays.

Why?

A number of sources tell me that there will be additional shooting for Iron Man 2, although Paramount denied this to me when contacted last night. Tonight Jon Favreau tweeted this: ‘Began “locking reels” today. It’s the beginning of the home stretch on IM2.’ That means he’s finished specific reels of the film in editing, and that they’re ready to go (although they probably still need mixing and FX and whatever).

Which means there are two possibilities: one is that there are upcoming shoots for Iron Man 2, but that they’re for specific parts of the movie and that Favreau is editing around them. The denial I received may have been a very standard thing, since studios never like admitting they’re doing reshoots. I’ve explained it before but it bears repeating: reshoots can be a vital part of the process, especially after editing reveals the nature and shape of a movie. Lots of films change or really come together in editing, and a director needs to be able to go back out and pick up new shots or scenes to fill in the gaps. That’s very normal, and as far as I’m concerned, nothing to be worried about. In fact, it’s probably a good sign.*

The second possibility is the one that has your geeky mouth watering: Downey is gearing up for some kind of Thor cameo. That movie is filming right now, and it’s the penultimate film before The Avengers, so a Stark cameo makes a whole ton of sense. In fact, we just learned that Clark Gregg, who plays SHIELD agent Coulson, will be in the movie, so there’s lots of room for Tony Stark to show up.

It has to be one of these two things… and it could even be both of these things. If Downey is suiting up as Tony Stark and doing the shoots at the same lot where Kenneth Branagh is doing Thor – well, why wouldn’t he wander over and say hi?

* Updated to add: this is probably especially a good sign for Iron Man 2. My understanding is that, like on the first movie, there was a process of on-set discovery with this movie. Favreau and Downey are pretty open while shooting, and reshoots could be done to help reconcile the stuff they came up with later with the stuff they shot at the beginning.