Some meta discussion: "xyz reaches/releases version number 234234.324234" is entirely meaningless and the best way to ensure that nobody will care about your release announcement. Your project may internally have a very well defined and entirely logical policy as to how exactly to change version numbers based on internal project changes, but from the outside this is 100% untrustable and invisible, meaning your 2.0 release could mean anything from "we rewrote the entire thing" or "a set amount of time went by" (see Firefox/Perl/probably others).
If you actually care at all about your release announcement being read, include in the title line the actual benefit the new version provides to people.
If you actually care at all about your release announcement being read, include in the title line the actual benefit the new version provides to people.