There was a lot of discussion going on (especially on pages 6 and 7) about the connections between Elantris and Mistborn. And I think that's really interesting. So here's my two cents, whether you want 'em or not:
Far be it from me to claim that either Elantris or Mistborn is formulaic, let alone built from the same formula, but there are some definite patterns in the religious and magical systems in the books. For instance, the Jindoeese are "soft-spoken and uncombative", calm and level-headed. Sounds a LOT like the Terris. Not only that, but the Derethi have a rigid structure like the Obligators and -- to an extent -- the Inquisitors. And, of course, the Korathi are the most "free" people, which inherently leads to class differences like nobility but also generally content "common" people who speak for themselves and have their own ideas. Although some of the Skaa were oppressed in the Mistborn trilogy, the Skaa/Nobility were a LOT like the Korathi in that sense.
In a similar way, it seems to me that there are actually three forms of "magic" in Elantris as well. Though we haven't seen much other than the Dor, it has been shown that the Derethi are able to manipulate bone structure to create creatures that live a long time and have super-strength, and who knows what other powers. Similarly, the Jindoeese seem to have some sort of speed augmentation power and superior concentration (Blessing of Presence? Just kidding), though they may also have others. And, in keeping with the themes present in Mistborn, Aon power is fueled entirely by the Dor, while Bone-Twisting (I dunno what you're going to call it) causes a great deal of pain and undoubtedly requires some kind of sacrifice. In addition, the fanatical devotion of affected Derethi to their cause seems uncannily similar to the influence of Ruin over those who are pierced by metal (on the other hand, Hrathen kept his sanity in spite of his augmented arm and didn't seem to need to struggle with any voices...) Meanwhile, if I remember correctly, the Jindoeese martial arts -- ChayShan -- required a period of slow movement that eventually built in speed -- which reminds me of Feruchemy -- just without metals. These ideas (I refuse to call them "theories" as a reader's ideas cannot be backed up through experimentation -- only by what an author chooses to reveal about his OWN ideas) are probably riddled with holes in their present form, but maybe that's because it's been a year and a half since the last time I read Elantris and we didn't really get to see many examples of Jindo or Shu-Dereth power.
There's also that thing in the Glossary about how many who enter Dakhor are never seen again. This may be simply because of how secretive Dakhor's warriors are, but it might also be because some of the initiates are used as sacrifices to empower others.
I do wonder, too, whether Domi and Jaddeth are "real" deities in Arelon, or if there's something else going on here. Is Domi the current "spirit" wielding the power of the Dor, while Jaddeth is master of that creepy thing they do in monasteries?
...Also, a thought on "Lerasium": Does this imply an alloy called Mallerasium or something similar which does...something? If that's the case, doesn't that bring the total to 18? Maybe there are 20! And since the "temporal" metals show multiple possible alternate realities, perhaps Lerasium and the quartet it fits into has something to do with alternate realities/dimensions/futures/pasts as well. This is all just off the top of my head, but since Lerasium grants Allomancy (and, apparently, other powers if it's alloyed with other stuff) perhaps Mallerasium permanently inhibits powers. Meanwhile maybe there's still ANOTHER pair of metals even Sazed doesn't know about (or simply didn't want to tell about) that similarly affects time and space.
And and and...
...Even Warbreaker has two "magic" thingies: the Harmonics and the Hues. Hmmmm. Aside from that, I still wonder what the Pahn Kahl actually do believe. Several characters described that religion as "simple", but there's never an explicit definition of the Pahn Kahl religion. Then, too, there's ichor-alcohol, which seems to enhance the powers of Breath when used for the creation of a Lifeless, but which (as far as we've seen) is just a special chemical otherwise unconnected to BioChroma. Is there some other form of magic in the Warbreaker world that we somehow don't know about yet? Alchemy?
If not, there's still something interesting about the ways BioChroma can be used:
-In creating a Lifeless or similarly imbued artifact (such as Nightblood), power is eventually lost as the Lifeless will eventually "run down" and the Breath cannot be recovered. This is especially true with Nightblood, since he "eats" Breath.
-In Awakening, power is maintained since it can be recovered in the exact same amount after its job is done.
-In Returning, power is gained since an incredibly powerful Breath is bestowed on an individual who did not have that much before (unless said individual was an extremely rich and powerful Awakener...but such an individual is unlikely to Return, given what we know of the Warbreaker theology). Although the Returned also consume Breath, they do so at a slow rate and only one such as Vasher would have consumed enough to constitute "loss" of Breath (even if a Returned lived for decades, I think the Breath it was granted from the beginning is still more powerful than the sum Breaths consumed).
This follows the same pattern as the other books. The only anomaly is Alcatraz (both Talents and Lenses essentially derive something from nothing, and both can be used for either good or ill), but many of us speculate that Alcatraz's magic is unrelated to the "adult" novels.