I think we just need to cross our fingers and pray that Drew Stubbs pans out. One thing he can do is play gold glove caliber defense and get on base. Even with all his struggles last season he still got on base at a respectable .364 clip. This year he's at .373. His power isn't developing yet but his OBP skills are nice. If he can play gold glove defense, get on base at a .360+ clip and steal 30 bases in the majors then he could really be one of the better center fielders in the league. Best case scenario is he's ready to take over CF by 2010.
Another intriguing CF option is Shaun Cumberland. He's a 23-year old prospect currently hitting .294/.396/.522 - .918 OPS in AA Chattanooga and he can play some solid center field.