http://www.gaisler.com/index.php/products/ipcores/soclibrary
Also SPARC but with plenty GPL. Has a quad-core, too, with all of them designed to be easily modified and re-synthesized. :)
I'm assuming it'd be expensive, as it doesn't appear anyone's doing it...
already existed - but apparently not (except for targeting FPGAs as you mention) ?
The analog stuff he mentioned is really tricky on any advanced node. Everything is difficult at least. It all needs good tooling that's had around a billion a year in R&D (Big Three) going back over a decade to get to the point they are. OSS tooling is getting better, esp for FPGA's. However, open-source ASIC's are going to happen with open source development model. Like many great things, they'll be built by teams of pro's and then open-sourceD. Gotta motivate them to do that. Hence, my development models in the other post.