Right now, only 4 of the top 10 picks have signed. The top two had a head start on the process because the teams knew who they were picking. In OAK, DHB not surprisingly signed ASAP.
Crabtree would be foolish to take a standard offer since he brings added value, and the 49ers would be foolish to just pay a premium, esp. for a player at a position they are somehow well stocked at (WR).