I know this conversation will probably drag on for a while and it's still purely speculation at this point, so if you're already over it don't read any furter.
With that said, although I do still think Speight is probably #1 on the depth chart right now due to age, experience, and a number of quality games last year (with some bad ones too), based on what I've seen so far in the spring, and in particularl the last spring practice video, Peters looks way better than Speight.
Speight often threw to one WR without looking at other options. Speight often through into traffic or good coverage, rarely completed his passes, and did not use any head, eye, or ball fakes to decieve his intentions to the defense.
Peters on the other hand looked sharp, completed most of his passes, and found open recievers quickly. Caveots apply. I don't know who was playing defense on those recievers or even who most of the recievers were at the time other than the TEs that were easy to spot. And, it wasn't live so the QBs knew they weren't going to get hit. But, based on what I'm seeing this spring, Peters may be our guy next year unless there is a big swing in how these guys are performing in practice. I don't see Harbaugh as the kind of coach to just give it to Speight based on last year if he's being out-performed by Peters in practice.
For those who haven't seen the video, here's the link from Scout: