I don't believe the people in charge were merely trying to attract viewers or capitalize on the success of the flashbacks in Lost's story structure, as I've heard other people say. However, I will say that a flashback episode--though difficult to pull off--has the potential to be a series classic, and that's not what I saw in this case.
Watching the characters in action before the bombs went off could have been extremely revealing and surprising, but it seemed like the main point of this episode was to introduce Sarah--something that could have been done briefly in the following (or preceding) episode. The Hawkins' story was interesting, but not particularly moving--it didn't require an entire flashback episode to tell. The flashbacks showed a few excellent foreboding moments, but I didn't feel like it introduced much new and crucial information to the story. It was fun to watch, but it didn't measure up to any of the previous episodes.
The timing for a flashback episode was perfect--right after we discover that Roger has returned to Jericho, they create tension by making us wait until after the flashback episode to see what happens next in the present. I just wish the execution was a little bit better.