There is not that much happening on the island, except of an experiment Daniel is doing that is worth talking about in a reivew, but the dialog is interesting and we get more information about things that happened in the last two episodes.
The Flash-Forward is far more interesting this time. Sayid seems to be an assassin in his life after the island. The flash-forward episodes are exactly what LOST needed at this point. With a few excetions, we know enough about the past of the survivors. But after the season finale of season 3, everyone wants to know who is getting off the island and what happened to them. The way the FFs are done is brilliant. They tease us, get us exicted about what will happen soon but don't give away too much.
If LOST keeps on building tension like this, we will get a big bang around Mid-Season. This might be the biggest year for LOST.