Not a lot to say. I thought Ron Moore would give us a double-peak - some action around 4x17 and 4x18 and then a grand finale, but it seems now certain it will only be Grand Finale.
Basically we're still in positioning mode, getting everything in place for a major Cylon space home (Cylon "colony") versus human space home (the fleet) final battle / lovefest.
It goes something like - Adama moves flag to baseship, farewell Galactica old girl,
Sam jumps Galactica to see The Beings of Light or whomever is running this show,
baseship Hybrid maybe jumps to Colony?
Zak Adama or The Architect or Beings of Light or somebody (14th colony of hybrid human-Cylons who found peace and enlightenment? Ascended beings? Lorne Greene? I'm running out of ideas) Explains All and then Cylon home and human home learn home is a place where love makes its nest or some damn thing, Hera projects a vision of the Opera House, Baltar and Caprica Six reconcile, the dying president smiles upon them and we all live happily ever after.
(Can you tell I'm getting a bit tired of Moore dragging this out?)
* Kara definitely human - which means her father was NOT Model 7 Daniel
* never plug a robot into your ship (it's like they've never watched Star Trek: The Next Generation - oh wait, that's where Moore practiced his craft)
* Sam has The Knowledge what with being some combination of ascended being and Liam with some access to the music of the spheres that unifies everything
(when you think about Cylon "organic memory transfer" technology, it has to be something about tapping into some sublayer of consciousness, otherwise how does it just pick consciousnesses out of the ether and install them in new bodies - which of course begs the question, why just Cylon consciousnesses? why can't you just pick ANY dying brainwaves out of the celestial harmonies and download them into a new body? surely that must be what happened with Kara?)
* Cavil will end up like Sam, becoming a ship (Cavil has stated pretty clearly he's more interested in being machine than man)
In summary, my current best guess is just an extension of previous "all shall be made one" theories:
Kara Thrace, thanks to Sam jumping her to the right destination, finds the puppet masters, who are either some beings tapped into the oneness of it all ("Beings of Light") or an unknown 14th colony of hybrid Cylon-humans. The future is Cylon-humans. "The end of humanity." Hera is their future. Baltar and Caprica Six are second human-Cylon couple. The end.
PS Ron Moore, please give us one last space fight at the Colony, before Kara and Sam jump in with the answers that bring Peace.
PPS Zak Adama is a Cylon