At long last, Intermorphic's iPhone SDK application has been activated, we've got our certificate, and we've got Mixtikl running on my iPhone! Exciting times... :)
Sound quality is great, the UI is responsive and things are looking good. :-)
It'll be fun getting Mixtikl tidied-up for the iPhone; Tim's already created a great new iteration of the skin that we'll release first for the current platforms (Windows, Mac, and Windows Mobile). We've also been generally improving the workflow and usability of Mixtikl, and will be using the reworked Mixtikl as the basis for some neat demo videos.
We hope to be in a position to submit Mixtikl to the App Store in the next 3 months or so, but time will tell...! We certainly don't intend to release it until we're totally happy that it offers a polished iPhone experience.