The Sun processor issue is down to lack of use outside some environments Sun hardware is a rair commodity to see an when you do see it it's running Solaris (a evolution of the Sun OS that the Linux Kernal it's self is based on), Sun's hardware is mostly proprietary although they do offer intel equivilents of the hardware they try to push there own branded processors more than they do intels.
I think that is the main reason support for Spark processors has droped from the main release, they havent and wont drop support for multi core processors from the big two vendors as it makes no sense to do so.