[octothorp]

Oh man, yeah, Tom Bombadil would be too much.

My best guess and reasoning for the meteor man identity:

Spoiler!

I think there are strong hints that it's gandalf. There's a passing resemblance to a young Gandalf (or as young as an old man can be), and the way he spoke to the fireflies was very reminiscent of the way Gandalf spoke to moths. Radagast would also have such communing-with-nature abilities, and I think if we're strictly following canon, would be more natural at that than gandalf. Also, the path of the meteor can be pretty obviously seen as coming from the West, as in order the characters looking at it are in Lindon, and then Arnor, and then the Southlands (seen closer to the horizon), then Fangorn, and lastly the Harfoot home near the Anduin, so it's definitely something coming from Valinor.

But the main reason is that it makes sense is that all the movies lean heavily on Gandalf's love of hobbits, and so having a disoriented Gandalf appear in middle earth near the Harfoots and being nursed back to health by them would be a nice origin story for that friendship.

Also, despite my earlier objection about any Istari in middle earth in the 2nd age, I see that in the lotr wiki there's a reference to Gandalf (then called Olorin) walking in middle earth, unknown, before being selected as one of the Istari. I'm not sure what the source of that is, but second-age sources are all over the place.