I think the veracrypt project is great, except that it broke compatibility with old truecrypt files/drives. Since you are going to collaborate, I think it is important to work towards maintaining backwards compatibility for future releases.
It would also be very simple to code: when opening a container, one would first run 1000/2000 hashes and check for the 'true' string, and if that does not work out, run 30000 or whatever veracrypt does and check for the string 'vera'.
One could easily expand this for other iteration counts/string combinations as well.
Many users have terabytes of truecrypt encrypted containers and drives, and to simply break backwards compatibility would do them a big disservice. Unless a fundamental flaw in the old container structure is found, of course. But thus far, TC looks safe. So please keep future versions backwards compatible.
Otherwise best of luck with the project!