First, the bad news for anyone who's reading "The Flash" #12 in order to see exactly how the DC Universe transforms itself into "Flashpoint." You won't find that here.
With that said, though, what you do get is certainly related, if not a direct connection. As "The Road to Flashpoint" wraps up, we get an answer (if not terribly satisfying) on the mysteriously aged victims, and Professor Zoom reveals some of his plans. It's not bad, but it's also lacking a bit of zip that earlier issues had (no pun intended). This issue has a lot of exposition packed into its pages, with an almost frantic wrap-up of everything going on in this comic.
It probably doesn't help matters that originally solicited for this month was "The Flash" #13, advertised as the conclusion to "The Road to Flashpoint." Presumably some of the material meant for there might have ended up here, but at least for now, the series is over with a frantic scramble from one location to another, eliminating characters from the roster and wrapping up some loose threads. Of them, it's the stories involving Bart Allen and Patty Spivot that suffer the most; both felt like they were going somewhere, but get short shrift here. Hopefully once "Flashpoint" is over and the new plans for a "Flash" comic are revealed (perhaps a long-rumored "Flash Family" title?) their stories will continue there.
Scott Kolins, who must have some Flash-like abilities of his own in order to turn out two issues of "The Flash" so quickly, handles the bulk of "The Flash" #12. There are some pages where you can see Kolins (understandably!) cutting corners in order to make the deadline of simultaneous publication with "Flashpoint" #1. Characters sometimes appear much more rough-hewn and lacking in detail than you'd expect. When the Reverse-Flash is first attacked, for instance, it's so sparse that it's hard to believe Kolins is still drawing the comic. Kolins does the best he can under the circumstances (the final page with Bart and Barry, for instance, looks much more like Kolins' current style) and while it's not all quite up to par, it at least never looks bad.
Francis Manapul tackles a five page sequence here as well, and on the bright side it looks gorgeous. It's a firm reminder of what an amazing artist he's become (even if he it's becoming increasingly clear that he's not meant for a monthly ongoing comic using his current style), with soft lines and great posture. Look how Patty leans against the wall, for example; it's got a bit of a dejected slump in its body language, and it says more about her emotional state of mind than all of the dialogue in the comic.
As for the final two pages of the comic, the direct lead-in to "Flashpoint" #1? Well, if you didn't read this comic before the big comic of the week, you haven't missed a darn thing. It feels hastily tacked on; as a prologue, it doesn't quite pan out. Still, even with this weaker final issue, I've enjoyed "The Flash" from Johns, Manapul, and Kolins. I'd love to see some or all of them connected to whatever series will follow on later this year. Until then, "The Flash," adieu. Your latest series ended with a whimper rather than a bang, but we had enough fun up until now that I'm willing to forgive and forget.