I've seen the Mill CPU come up a number of times -- maybe because I subscribed to their updates and so I get emails about their talks. They're getting a bunch of buzz, but every time I look at their docs or watch their videos, I can't tell -- are they "for real"? They certainly claim a large number of benefits (retire 30 instructions a cycle! expose massive ILP!), but it's hard to tell if it's just some guy claiming things or if there's any chance this could happen.
They make a big deal out of their founder's history: "Ivan Godard has designed, implemented or led the teams for 11 compilers for a variety of languages and targets, an operating system, an object-oriented database, and four instruction set architectures." At first I thought this was impressive, but I decided to look into it and I can't find any details about what he's done, which isn't a good sign. If we're counting toy projects here, I've defined 5 languages, an ISA, and an OS -- which is why we don't usually count toy projects.
They revealed in one of their talks too that they don't have anything more than a proof-of-concept compiler for their system... but they have "50-odd" patents pending? They said it's "fairly straightforward to see" the results you'd get "if you're familiar with compilers", and when more hard questions were asked Ivan started talking about his credentials. I feel less convinced...
This sounds like a lot of stuff that's been attempted before (ex Itanium) -- unsuccessfully. They have some interesting ideas, but no compiler, and (if I remember correctly) no prototype processor. It bugs me too when people over-promise: Ivan talks about what they "do" rather than "plan to do" or "want to do", or "have talked about doing", which feels disingenuous if it's just a paper design right now.
The more I look into the Mill the more I don't think it's real; I think it'll fizzle out soon, as more people push for actual results rather than claims. It's a shame, since I think it's always cool to see new processors with new designs, but I don't think this will end up being one of them.