For those of your looking for Starting Pitching help (like myself, losing Brett Myers to the Bullpen, Felix Hernandez to an injury, and Scott Olsen to terrible play), Philip Hughes will be called up by the Yankees to start Thursday's game against the Toronto Blue Jays.
One of my favorite pitching prospects, Hughes should be a top pitcher for years to come. Whether or not he will reach expectations this year is yet to be seen, but he has the minor league resume to allow us to think he may be ready. His command was apparently shaky this spring, but if he can strike out 7.5 per 9 IP, walk 3 per 9 IP, and get a 50% GB Rate he could end up as the AL Rookie of the Year. I've touted Hughes several times already this year, so to read more about him check out those pieces.
Hughes has not yet been added to Yahoo! leagues (quite possibly the thing I hate most about them), and if last year was any indication it could be as late as Saturday before he is available to pick up. Constantly monitor the Yahoo! free agent pool, and snag Hughes when he becomes available.
Two other top SP prospects who could have an immediate impact upon being called up are Tim Lincecum (SF) and Adam Miller (CLE). Watch for these guys as well.