If you have the E-3, then by all means try and splurge for the SWD version of the 50-200mm. If you want to capture birds, etc. go with the 70-300mm, which is really a rebranded sigma. It has a long reach but is very slow. However, if you had to choose between the old 50-200mm and the 70-300mm, go with the 200mm.
I just confused myself with this post.