On her blog, Barbara Nicolosi writes: It doesn't add anything narratively to be dark just because you can, or to leave the audience feeling nauseas and grief-stricken because their beloved characters have been tortured to no meaningful end. It isn't darkness that makes us love BSG, but rather the characters fundamental heroism in spite of their dark impulses. I'm just afraid that we aren't going to care for these people by the time they ever do dock on earth . . . .
She pretty much hits the nail on the head for me (read the rest here). After watching last night's episode of Battlestar Galactica, "The Road Less Traveled," I flipped off the TV and found myself really missing the first two seasons of BSG. (The feeling could have been accentuated because I found Thursday's episode of Lost disappointing also--too much plot and filling-in of minor holes and too little character development; and is anyone else getting tired of Jack's whining? But, back to BSG . . . .) There was darkness in those seasons as well, but also hope. There's way too little of that in the last few epsiodes--and I've got an uneasy suspicion that the hopes that some are reaching out to (like Tyrol to Baltar or Starbuck to Leoban) are black holes masquerading as light.
But like Nicolosi says at the end of her post, "there is still time."