Not sure if this has been covered on another thread yet or not, but according to the official Spring Training Notebook sent out by Rob Butcher, there are only 10 players on the 40-man roster that don't have options, if it would make a difference for last-minute transactions close to Opening Day:

Bronson Arroyo, Juan Castro, Francisco Cordero, Ryan Freel, Scott Hatteberg, Jeff Keppinger, Brandon Phillips, David Ross, Javier Valentin and David Weathers

Of course, looking at the list, you have to figure the roster spots for most of all these are pretty well set, barring injury or trade. < That's the consensus opinion reading other people's 25-man predictions, not mine (of course, we all know Castro wouldn't have much of a fan club if a poll was taken of all the RedZoners though).