Adapting a movie that bombed into a series?????
The series might actually be able to do well for the same reason the movie struggled. The book absolutely cannot be made into a television series. Without spoiling too much, the television series would end too soon. This is the same situation with Flashforward... if they just put the book on the small screen, it wouldn't work as a television series, because the series would end too soon.
So in both of these cases, they need to make a television series out of the featured plot device of the series, but craft a new story around that device.
And in each case, the plot device is an excellent foundation for a television series. Again, in each case, the plot device reminds me of the Stargate, or of the Time Tunnel, or of Shawn Spencer's powers of observation in Psych, or perhaps even of Beta in Defying Gravity. A great television series can come from building a world around such a device that provides such a fertile ground for building stories about people we care about experiencing these paranormal things.
I don't consider this a spoiler, since I'm just guessing, but I think in order for Flashforward to work at a series, they're going to have to use the flashes in a repetitive manner, happening frequently over time (instead of how it worked in the book). Similarly, instead of The Time Traveler's Wife television series being about what the book was about (can't say, because that would spoil the book), instead I would guess that the overlapping of the two main characters life wouldn't invariably lead us to an ending (as, of course, any good book does).
Instead, in both cases, my hope is that they build a television series that is about the human relationships between the main characters with regard to their reactions to the paranormal experiences that each of the respective plot devices evoke.