Sorry if this question has been asked before...but who or what, exactly, is the All-Maker? The best guess that I can come up with is an early Nordic version of Anu...and I may be completely wrong. A little help here guys?

don't know, I have to replay dragonborn

Chances are he's Anu the Everything.

One thing to keep in mind, is that the Skaal are deeply connected to the Dragon Cult. It's likely their beliefs are more Anu-aligned due to the Dragon Cult's veneration of the Time God.

All of Nirn's religions are essentially variations on a theme (with the exception of Argonians and the Hist, and possibly the Yokudan pantheon). They all revolve around the IS/IS NOT of Anu and Padomay. Stasis and change, potential and entropy, everything and nothing, matter and anti-matter, order and chaos; all of those things and more are Anu and Padomay.

The Skaal don't have the standard pantheon, but their beliefs are still tied to this duality. They are animists; they believe that everything has a soul. This fits in neatly with the idea of subgradience in the Aurbis, that every living soul is a smaller fraction of the original Godhead. (Gods are big fragments; mortals are little ones.)

So the All-Maker is associated with Anu. Conversely, the Greedy Man is associated with Padomay. To quote Brenz0r, who said it better than me:

(Okay, Malak got there first!)