Yes - I did watch it - but ... rather disappointingly it only seems to show the opening address.
A 770 did feature - in the part about location-based services.
It was up on the screen alongside a new phone.
No mention of 870 or Linux. Symbian was mentioned in that same presentation.

I've posted a question to one of the bloggers at the event - one who has a 770 - to see if there are any 870 floating around.

There were announcements of mobile phones (4 I think) on day 1.