If anything significant has yet to be seen, then it must be tested for some time before release. And if gets released to testers, then word will leak.
Thus, Apple would want to hold an official event to preview the additional features, letting the news out in their own way. And this event would not be the release date--it would precede the final testing, and might name the release date.
June release sounds reasonable to me, with an "unveiling" well before then. There's no obvious reason NOT to preview the new stuff publicly: it would generate publicity, and Vista's already out if they're worried about stuff being copied.
New stuff that touches on entirely new business areas might be worth keeping secret--but not once it's being widely tested. There are no secrets then.
BTW, it's amusing how many people each have their own list of the "one or two" great features of Leopard, and call the rest useless... and for each person it's a different list
So I'll name MY top feature:
* All the little stuff that doesn't make a good headline but adds up to a more productive experience every day. Each OS X release so far has been packed with these, and make OS X worth my $99 (Amazon) every time--even without the "headline" features. (Which, in the case of Leopard, DO sound pretty big to me--even the ones we know already.)
Re the secret features, I'm not expecting much. Apple-followers get themselves worked up that something great and revolutionary is coming every time, when of course the reality is that the new stuff is only great and revolutionary SOMETIMES. Maybe Leopard's secrets will astonish me, but I'm betting they will just be a little more icing on the cake. Like a new Finder. I finally really like the Finder as of Tiger, but it has its rough edges and I'd love to see a replacement.
And if Leopard's known new features don't impress you, I bet you're REALLY not excited about Vista
(Yes, I know, Vista compares more closely to Panther or Tiger.)
