It's a bit too early to really get into specifics, and as a general matter the composition of the class is still pretty fluid at this point, just because so much in terms of player development, attrition, injuries, and early departures for the NFL draft has obviously yet to happen as it relates to the 2015 season. That said, I think jps has a nice general summary above of where we will likely go.
For now, I think we focus heavily on safety, linebacker, and wide receiver. Offensive tackle will be a priority again just because that's the nature of the beast in the SEC, and we'll try to find another top QB prospect. We will nab a couple of tailbacks, and I hope a couple of more college-ready corners (i.e. not "athletes" or long-term developmental projects). The biggest X-factors for the time being in terms of class composition is where we are heading schematically at tight end (traditional end-of-line blockers v. hybrid types like Howard and Flournoy-Smith) and whether the staff is sufficiently satisfied that we've gotten sufficiently more athletic along the defensive line in the past two classes. My hope is that we sign three or four more DL who fit the "quick twitch" mold, in Saban's parlance, but not sure that will actually happen just yet.