We forked this system four-and-a-half years ago, and have done a ton of work in the open; at this point, we identify ourselves much more strongly with illumos than we ever did with Solaris. We also have plenty of folks who have contributed to illumos who never worked for Sun and never contributed to Solaris; to us in the illumos community these are not "Solaris fragments" any more than they are "SVR4 fragments."
As for Oracle, trust me that I hate them as much as anyone[1], but raising Oracle with respect to illumos absolutely is FUD: the project isn't related to Oracle in any way (or any more than it is related to AT&T, which also holds copyright). Even where there are Oracle copyrights, this is open source, and the CDDL is an air-tight license that (sadly) has been battle-tested by Oracle's own lawyers. Thanks to the explicitness of the CDDL around things like patent, there really isn't much that Oracle can do. And indeed, given the massive Oracle-owned Solaris patent portfolio, the same cannot be said for other non-CDDL systems that may infringe those patents -- illumos is (perversely) the only one actually sheltered from Oracle bad behavior in that regard.
As for Oracle, trust me that I hate them as much as anyone[1], but raising Oracle with respect to illumos absolutely is FUD: the project isn't related to Oracle in any way (or any more than it is related to AT&T, which also holds copyright). Even where there are Oracle copyrights, this is open source, and the CDDL is an air-tight license that (sadly) has been battle-tested by Oracle's own lawyers. Thanks to the explicitness of the CDDL around things like patent, there really isn't much that Oracle can do. And indeed, given the massive Oracle-owned Solaris patent portfolio, the same cannot be said for other non-CDDL systems that may infringe those patents -- illumos is (perversely) the only one actually sheltered from Oracle bad behavior in that regard.
[1] https://www.youtube.com/watch?v=-zRN7XLCRhc#t=34m0s