He is on the 40 man roster, according to Redsox.com and on Soxprospects.com, so he could be seen on the Sox as early as next seasoon as a September call-up or even in Spring Training.
http://www.soxprospects.com/players/iglesias-jose.htm
this says that he is comparable to Orlando Cabrera.
Hitting is a question mark and his fielding is amazing. it says possible gold glove SS.