Yeah, that's an interesting avenue of speculation, Tamer! What vehicle, indeed. We got our ESB goodies this year, with the AT-AT, Twin-Pod Cloud Car, Snowspeeder, and TIE Bomber. They just dropped a Slave I through the CW line, so I'd be willing to bet a repaint/repackaged Slave I *could* be it, if the CW vehicle was a new mold. But if we accept the idea of Hasbro wanting to move on from ESB after the anniversary year and NOT wanting to tread on ROTJ's 30th too soon, What else is out there?
EpI - Could a new Naboo Starfighter (N1, I think?) be in the works? What about a Trade Fed transport (MTT, I think?)?
EpII - *ARE* there any EpII vehicles that haven't been done yet?
EPIII - um, I haven't watched it yet, so I have no suggestions.
TCW - as above. They've recycled a number of older vehicles into TCW packaging - AT-AP, Fighter Tank, AAT - and dropped a few doozies on us - swamp-speeder, droid bomber, (did the droid gunship release yet?) and the radio-controlled Hailfire droid. Is there a Jedi General figure who doesn't have their own exclusive Jedi Starfighter yet? If so, this could be their year!

But we're looking at the Vintage line, so I'd leave TCW speculations out of this. (assuming of course that the next big vehicle is a Legacy and not a TCW-specific selection)
SW - We're about due for a new "Luke's Landspeeder," I think. I can't think of anything else, as we've had a nice Y-wing and X-wing and the BMF; Vader's TIExI is out on local shelves as a repack/rerelease. *Maybe* we could see a rerelease of one of the standard TIEs?
ESB - nothing new from this, see above
ROTJ - again, with ROTJx30 coming up in 2 years, I doubt we'll see anything from this movie until 2013.
So... that's my take on the playing field. Other thoughts, anyone?