This should have published earlier today.
I was planning on adding a link to the 40 man rosters for each team prior to draft day, but stumbled upon this site-MLB Depth Charts- when reading Jonah Keri's NL All-Zero-to-Three Team over at Fangraphs on Friday.
This site has a list of the 25 man rosters for every major league team, and the blogger-Jason Martinez-describes his methods for determining the 25 man rosters he published. Just having a list of 25 man rosters on draft day is a valuable source of information should you be deciding who to take with your next pick, or want a better idea if a 4th outfielder or backup infielder is on the 25 man roster to push a starter and take at bats away.
I will add this site to the list on the lower right had side of the site for your future use.