Unless Mike Johnson is the second coming of Mike Shanahan, the niners are probably going to crap out the season and pick in the top 10. If that happens, Singletary is gone (his contract is up anyway) and a (probable) offensive coach will be brought in -- there is enough talent on defense.
With that being said, the new coach (and probably GM too) will take a QB. Lucky for us, this is an excellent year for QBs.
The top four QBs, consensus, are Luck (Stanford), Locker (UW), Mallett (Ark), and Ponter (Fla State) -- the rest (Stanzi, others) are probably 2nd or 3rd round picks.
Who would you take? Personally, I would take Luck and go back to the West Coast Offense with either Harbaugh or Gruden or Billick. But Luck will probably go #1, so I would go with Mallett after that -- his rocket arm and mobility in the pocket are too much to pass up. After that, I go with Ponder because I think Locker is too raw and erratic to be a safe choice.