I know I bought a tamron lens that was up to 300 for my Pentax and I'm sure there are other makers that are putting lenses out for the Sony also. The lens I bought isn't the top of the line model but works for my needs. They also have very expensive lenses made by other companies, just too poor to justify it right now.
Ace does have a Sony and I believe he has been very satisfied with his also. Take a look at some of the photos he's taken in some of the photo threads to get a look at what his can do also.