There are only 2 words to describe the finale. Holy. Frak.
I'm not going to put any spoilers in here, because this finale would be worth watching the miniseries, and all of seasons 1 and 2 just to get to the point that you're ready to watch this. It's that amazing. I can't remember a series that took such a gamble with rethinking the show so completely.
Ronald Moore described the finale as an attempt to roll hard sixes. I think he's pulled it off. BSG wasn't stale - yet - but was beginning to fall into the usual
10 print "oh no! run from the bad guys!" 20 pause 30 print "oh no! more bad guys!" 40 run 50 goto 10
formula. 2 seasons in, just as the show is really hitting its stride, they decide to be preemptive about it and completely rethink the genre. I said no spoilers, so I won't say what they did, but I can't frakking wait to see season 3. This changes everything.
Kudos, Ronald! I'm sure the network guys pushed back a little - not wanting to take a risk with the highest rated show they've ever had (IIRC). But being able to do something so radical is pretty amazing by itself. Just be glad that Fox isn't bankrolling this one!