I think it's probably best if MyrU stories base their divergence points on familiar events in the televised and filmic continuity, for the sake of maximum audience accessibility. Even granted that the MyrU books would have limited appeal outside the audience that already reads Trek Lit, I doubt every Trek Lit reader has read Destiny or any other single story.
Besides, pretty much the only story to be told if the Borg had won would be "Everybody dies, the end." Unless you want to do a story about a ragtag, fugitive fleet of survivors on a lonely quest for a new home while a relentless robotic horde pursues them bent on their annihilation. Which has kinda been done already a couple of times.
(And just a reminder, let's take care to avoid getting specific about story ideas.)
Well, yes...AND no.
As a fan of TOS, TNG, and latter seasons of DS9 and VOY as well as the movies, I had a nodding familiarity with the most of the points of divergence. I had to borrow a friend's boxed set of ENT Season 4 and watch "Terra Prime" to get the full effect of the Enterprise story. Various and sundry sources (TrekPedia and Memory Alpha) filled in most of the rest of the details.
And again, with no solid sales figures to back up this assertation, I will nonetheless say that the Destiny trilogy was the most anticipated and discussed TrekLit event of the last eighteen months (I know; Mack grins as he rolls about in a swimming pool filled with royalty monies, the rest of you boo and hiss as you consume your Ramen noodles and engage in post-Destiny cleanup...). I'm just saying, I suspect that most MyriadU readers have also in all likelihood also read Destiny. And have probably thought, "What if..."
Just because the Borg "win" doesn't necessarily mean they have really won. I think Guinan said something about that while the Enterprise-D was hiding in the nebula during "The Best Of Both Worlds", to the effect that as long as there were a handful of humans left, humanity would prevail even if it took a millenia. Wiping out 95%, or even 99.99% of a species doesn't necessarily make them utterly extinct, especially if the few who are left are canny, resourceful, and vengeful...I doubt you would see the hand-wringing of Geordi LaForge over the dubious morality of thalaron-based weaponry, etcetera, at that point.
I understand your Galactica reference; believe me, that was the first thing I thought of when pondering this possibility, but I was thinking more about all of the other Federation ships that were too far away to be recalled to participate in these events, as well as Federation outposts and those ships and stations of other Alpha/Beta Quadrant powers far enough removed to have time to pack up and flee...and plan. Certainly someone more imaginative than I (like you frackin' guys...) could find a way to tell such a story without siphoning off Galactica.
Christopher, I remember your aforementioned caution about discussing specific story ideas from a thread about a year ago and I appreciate you mentioning it again for all of us...but a Myriad Universe story based off the rich possibilities of the Destiny events just smacks of (and envision early Steve Martin stand-up comedy here...)"Duh-UH-uhhhh!"-class obviousness.
Frankly, I'm surprised that Mack didn't hand over a Myriad Universe Destiny novella after the third Destiny book went to press, a la a Director's Cut DVD "alternate ending".
Of course, he was probably too busy purchasing his yacht and a helicopter to bother with it...