Thy King wrote...
I too agree that Shepard should be promoted. I think commodore would be fine, since in the released demo (not the leak!!) you see shepard commanding/leading a small quarian fleet. There might just also be alliance ships at some point.
I think the 'commander shepard has a nice ring to it' or the 'it is the games trademark' or the 'it just sounds better' is about as sad/lame as excuses go to not promote shepard.
I picked the commodore (or fleet captain) because then admirals (Hacket or Anderson) can still order shepard around, yet he also can command a fleet commanded by captains.
Spectres may be above the law, they do not actually have command authority, otherwise every spectre would use a fleet just because he can.
The only problem I have with Commodore Shepard is that I'd need to make an Afro Shep and play the Commodores while I play.

Also, epic chin Shep wouldn't be that bad.
Hmm. Brick House playing as Fem Shep runs through ME2 sounds appropriate. 'Cause she's a mighty, mighty, and built like Bro Shep apparently.

Also, running into TIMs base, I'd have to break convention and play "Hello? Is it me you're looking for?"