Julie and Kevin have teased us in an interview and said it will be this season or next season. But I'm not sure if they meant DE will be 'together-together', or if Elena will only figure out she has feelings for Damon.
I think Elena has to figure out she has feelings for Damon by the end of this season at least. Stretching it out into Season 3 is a bit much, but it depends on what kind of things the writers have in store for us.
