I can understand they are afraid that because of ZFS in some cases people will spend less money on buying hardware and some propertiary software, and they are right. Their hardware really doesn't matter what file system you put on it and features are you going to use of that file system.
Don't get me wrong - EMC makes really good hardware and software to manage it, they have also excellent support. But putting such restrictions is just plain stupid - I understand they want to force people to pay for Time Finder even if ZFS would be good enough or better not to mention cheaper (ZFS is free).
On the other hand if vendors like EMC starts to notice ZFS just after 6 months it went into stable Solaris it is good and probably means customers are asking for it.
ps. of course ZFS's snapshots and clones work perfectly with Symmetrix boxes and Clariions
update: in latest EMC's support matrix EMC now says:
EMC supports ZFS in Solaris 10 11/06 or later. Snapshot and Clone features are supported only through Sun.That's a good news.