Seems like a recipe for confusion and fragmentation. It certainly hasn't helped Linux.
Although my suggestion sounds like two different operating systems, it's really just about how it's marketed. Fundamentally the technology doesn't have to be any different.
Of course, if your OS is flexible enough things like tiling can be done as add on: http://www.nurgo-software.com/products/aquasnap
I say open up the ability to run optional desktop environments like we have in Linux. I can have my tiled window manager (I am sure 2% of users would LOVE it and 98% would HATE it) and then others could use one of the official desktop environments. No need for a whole OS version. Its bad enough we have Pro and non-Pro Windows 10.