1. Joe Haden - solid CB, but not in Champ Bailey territory. Could go earlier or could be enticing for a team to trade up to get to.

2. Bryan Bulaga - This guy could fall to #13 and now with the rumors of Al Davis possibly taking Iupati at #8, that changes the flow of OTs and where they go. Bulaga's not a LT but could be a solid RT for years.

3. Jimmy Clausen - There is a chance Niners could trade both the #13 and #17 to Chiefs at #5. They would also get back the 4th pick in the 2nd round from Chiefs (#36) which they could use on an OL.
They could stand pat and see if he falls to #13. But if they seriously want him, the cost of moving up to get him is the difference between the #17 pick and the #36 pick.

4. Anthony Davis - believe he will still be on the board at #13 unless Al Davis takes him at #8, but I could see Al Davis taking Iupati over Davis.
Don't think Niners have him rated high enough on their OT board to take him here.

5. C.J.Spiller - clearly was more of an option before the Ginn trade. Niners may look at RB in later rounds.

6. Trade Down - Here's where it could get interesting. You have at least 2 trade partners who have a definite target in mind. Patriots - Dez Bryant and Cowboys - Earl Thomas. Both could be gone by #13, but if they are there, those 2 teams would seriously consider trading up.
With the Patriots, you get the #22 and the #47 in the 2nd round. With the Cowboys, you get the #27, the #59 (2nd round) and the #90 (3rd round).

I think the Niners have Charles Brown targeted at #17 and would take him there with all these scenarios (except trading up to get Clausen).
Personally, I don't feel Clausen is worth a #5, at #13 I'd be more okay with that.