The Ubuntu MATE flavour shipped one snap (pulsemixer) by default in the 17.10 release. You can find out more at their community thread on the subject.
Part of the reason for doing that on Ubuntu MATE in 17.10 was to test the waters. There’s some more work to do, but in Ubuntu 18.04 I’d expect additional snaps to arrive in other flavours, including Ubuntu proper. @willcooke can probably speak more to that.
We’re not currently looking at this as a piece of work. If someone in the community wanted to take a Core image and add whatever is necessary to get a graphical desktop and apps working, I’m sure it would be most welcome.