Adjustment of Status - I-485

Hi Guys, I had my I485 interview with my wife (USC) on the 24th of April, 2014 and everything was fine. The IO told us we gonna get the GC in the mail in 2 weeks and gave us a white printed paper that says recommended for approval. We never got the GC. We made infoPass apt, made an SR and made another SR with a level2 officer two days ago who said everything was fine and he doesn't understand the delay because its almost 90 days. He even said he was gonna contact them to release the GC immediately but then, USCIS send me an email today saying,
"Your petition/application is still pending consideration, and the Officer is preparing to send you additional correspondence, that you will receive in the coming weeks. We regret that we are not able to give you a timeframe for when we will complete the review of your petition/application." can anyone please tell me what this means regards the additional correspondence? Thank you