Worried about the secondary this year (nnamdi asomugha and cox look really bad- next man up Brock is worse). Teams are going to pick on them all year. Front 7 will be fine and if Reid continues to play like today, he's a definite upgrade over Dashon Goldson.
Offensively, O-line got stone walled, Kap's bad handoffs and improper clock management are worrying. The latter two are especially concerning as this was a problem last season (handoff issues were noticeably with Kap last year too). SF potentially has a potentially scary receiving core once Crabtree and Manningham come back. But yeah, Boldin is the muthafuckin man today.