I've been hoping that Alex would be able to post a brief update, as he's a lot more plugged in with the Mistborn line than I am at the moment, but he's busy with house guests this week.
Very brief update:
- We have a new line developer and a fresh talent team spinning up with the line now. This isn't particularly new - we sadly lost our first line developer, Will Hindmarch, a while back when he accepted a great offer to head up the Dragon Age RPG for Green Ronin - but it's also not something we've made a lot of noise about, and it's important for you to know that a) we have a team we're confident about, and b) they're deep in the process of bringing cool new stuff to your tables.

- Thieves and a whole series of digital and print products are in the works, including a full book on the Alloy era. The books will take some time, of course, and while we originally expected the first wave of digital products to be out by now, the first drafts didn't quite hit the desired marks, so we've sent them back for rewrites. (This isn't the fault of the developers or writers, by the way, but rather the natural growing pains of working with an all-new IP and not having the excessive resources required to soak natural bumps in the creative process.
Until Alex and/or Logan frees up, that's about all we can say about supplements at the moment - except to also mention that if all goes according to plan we'll be able to reveal (a few) more details soon-
ish. We're working on a new and more efficient channel to get intel out to you guys, and the first installment there should include some tasty details about upcoming Mistborn products.