Ben Zobrist hasn't hit a homer for fantasy owners in 2010, but he still has value - ESPN:
"When is it time to start panicking about struggling players? Is early May too soon? Do we wait for Memorial Day? After watching Tampa Bay Rays No. 3 hitter Ben Zobrist closely the past few days, my short answer on him is that I'm not particularly worried. He'll hit. The Rays think he'll hit. But that big goose egg in the home run category does stand out."
Mixed leaguers shouldn't have Zobrist active. Personally, I think the book is out on Zobrist thanks to the exposure of his hitting secrets via Mechnx.