So, for those who are as yet unaware, Asgard is the mythological home of the Norse gods. Google it if you want more detail.
In the Dresden Files, we can be sure it does/did exist in the Never Never as evidenced by (Vadderung etc).
The -gard element in Asgard’s name is a reference to the ancient Germanic concept of the distinction between the innangard and utangard. That which is innangard (“inside the fence”) is orderly, law-abiding, and civilized, while that which is utangard (“beyond the fence”) is chaotic, anarchic, and wild. This applies both to the geographical plane and the human psyche; thoughts and actions can be innangard or utangard just as readily as spatial locations. Asgard is the ultimate model of the innangard, while Jotunheim, the “Homeland of the Giants,” is the epitome of the utangard.
Midgard (“Middle Enclosure”), the world of human civilization, is, as the name implies, somewhere in the middle – not quite as innangard as Asgard and not quite as utangard as Jotunheim. But Midgard is a space enclosed, on the geographical plane, by fences, and on the psychological plane by norms and laws. This makes it much closer – at least in theory – to Asgard than to Jotunheim. In other words, Asgard is the divine model upon which the pre-Christian Norse people patterned their world.
It seems to me that the Jotnar/Jotuns could well be connected for the Outsiders (in the Dresden Files). This could be further evidence that the Aesir once were the defenders/guardians of Reality. Perhaps the Outer Gates and Wall are much older than the Fae. I don't think the Jotuns are necessarily Outsiders themselves. But perhaps they are related/connected like the Fomor and the Outsiders are.
Curiously, Muspelheim is home of the World Destoryers. So I would say that there is a relation there, too.