What has his performance been like?
Alen Hanson has made solid contact and hit for average at pretty much every minor league stop thus far. He hasn't hit with HR power with the exception of last season's 16 HR. He only has 5 HR combined across 3 levels when you exclude last season's stint in the SAL. Hanson has decent speed on the basepaths resulting in 20+ SB in each of his 3 minor league seasons thus far. The negative is that he has been caught in 27 of his last 73 stolen base attempts. Hanson has displayed decent patience at the plate at every level thus far. This means he probably doesn't have many significant flaws in his approach that can be taken advantage of at the upper minor league levels or MLB.
What is his current status?
Hanson is currently performing well at High-A. After a rough first month he has hit .300+ with a .800+ OPS in May/June. A switch-hitter, Hansen is really having trouble hitting LHP. He has a .320 average vs RHP and a .228 average vs. LHP. This could be the result of a small sample size or it could be a sign of things to come. This is the type of platoon split you want your players to have though because most of the time they will be facing RHP. He is certainly young enough to improve on the platoon split if it is for real. Hanson's 15 errors right now are something to take note of because if he has to move off of shortstop then he might not have a plus-bat elsewhere.
What can we expect moving forward?
I think Hanson is going to be undervalued by many. He may still end up with about 10 HR this year but going from 16 HR to 10 or less and never really having shown HR power before that will make people think his 2012 was an aberration. If he stays at shortstop he will still provide plenty of fantasy value, especially for deeper formats. Most leagues in which he is owned are 14+ team dynasties with minor league systems. Hanson will still be very useful in those formats. I've already seen him recently traded in one of my dynasties like he is of little value right now. That owner will probably regret that. Hanson is definitely someone to play close attention to. His power-stroke may come back, his SB success rate may improve, and there may be further indications on whether he can stick at shortstop for the long-term or not. Hanson has a wide range of outcomes but a shortstop who can hit .280+ with around 10 HR and 10+ SB is someone you don't sell low on after a slow start to the season. I suggest investing in him in your league if he can be had cheaply and the league is deep enough.