I see at least two of the Browns, Cowboys and 49ers taking a QB in this draft. Now if only two of them do, the Eagles' 2nd and the Rams' 1st could get them up to #8 (#7 on the pick trade charts, but I don't see the 49ers doing that with the Rams) to pick Wentz for instance.
I can't see the Browns NOT taking a QB - they have wanted one too long, and their new HC is going to want somebody to build around. The Cowboys just had a season torpedoed because their aging but still good QB got injured twice and missed most of the season. They nearly took a QB two years ago - they have more reason to do so now, and are unlikely to get this good a chance again anytime soon. With Kelly in SF, even if Koepernick is kept Kelly will want somebody to groom. Only if he prefers one or two of the available QBs and they are both taken will they go elsewhere imo.
And of course, other teams may be trying to move up.