I think the most we can hope for in terms of announcements is HD remakes. There was that Sega PR guy who heavily hinted at it, then there was the Shenmue Master interview where Suzuki looked a little cheeky when asked about remakes...and the whole PS4 campaign of bringing fan-favourites to PS4, with Shenmue no.1 on the list...I don't know -- it's probably just wishful thinking. Then again, he could drop a Kickstarter bomb at the end.
Speculation aside, I'm really looking forward to the post-mortem. I'm sure some amazing things will be uncovered.