I looked at the schedule for that day, and first they have the keynote, and then a break, and then they have "OS X State of the Union". This to me says that the keynote won't be so much about OS X, because they have a whole other section blocked out for just that. Maybe I'm off on this, but it seams like one more thing pointing in the direction of the 970 release...
The state of the onion is *very* techy, at least if last year is an example.
But the fact that the Steve keynote weights in at a whopping two hours, can only mean something big is being announced 🙂