I'd just like to point out that the 'Jamie spinning around' thing has been in at least 3 designer videos (Assembly Square, Silent Mary and Snow Speeder) so if it was a teaser it has been around a while. If Space Slug is a teaser, who knows how many times we'll have to see it before it actually pays off.
I for one believe that a UCS MF will be re-released if not this year, next year. My question is, how much better does it have to be to pay $700-800 for it. I have the 'original UCS MF' so for me it will have to blow me away to pay that much for it. It would have to be equal in size, with a fully detailed interior, constructed so that you could lift it without it falling apart (a la Slave I) and include a slew of really cool minifigs. Something like 7000 pieces.
So, what would it take for you?