I just discovered Yet Another Cool kickstarter project (as if my wallet wasn't bleeding enough already): Arakion. It definitely draws a lot of inspiration from Grimrock, but has completely different subsystems. Based on the available information, there will be a unique skill system, a customizable town to call home, and your choices throughout the game will affect future abilities. Items are all crafted in a system where abilities and stats on previous gear will carry over to some extend to the new items. From answers to the questions I've asked, I can so far add that you can toggle between real-time combat and turn-based combat, there will be at least three game difficulties, and based on my input, there may be settings to adjust game speed.
I thought this was worth mentioning to Grimrock fans, and I hope it doesn't constitute spamming (I'm genuinely trying to do the right thing, at least).
Grimrock on!

~ Daniel