I'm with topspeed on the flash forwards also. When you take a group of people and isolate them away from their normal lives like Lost does, it makes it difficult to be able to develop the characters using the usual props like family members, friends and circumstances. The flash backs provided the show with a way to help the viewers understand and empathize (or not) with the characters. But we've spent three years learning about these characters pasts. How much more about Jin's fisherman upbringing and corrupt, heartless father-in-law do we need to know?

The flash forwards add a whole new spin to the game. We've learned who these people were. Now we get to see who they become.

It's very exciting!