Here are two options I don't like:
1. Drafting Hasheem Thabeet. There's exactly one player that's built like Thabeet that's a star in this league, and Thabeet is not projecting to be the next Yao Ming. These days, centers (with a few notable exceptions including Dwight Howard) are role playing stiffs a la Eric Dampier.
The Grizzlies already have a center that's better than Thabeet. They don't need to draft a back up center with the #2 pick despite what Chad Ford thinks.
That brings me to another point. The Grizzlies shouldn't draft a guard unless that guard has the potential to be a star when paired with OJ Mayo.
If the Grizzlies find a guard (and I think Rubio qualifies) that has a strong chance of being a star paired with OJ Mayo, then the Grizzlies should draft him and trade Conley.
2. What I don't want to see happen is the Grizzlies draft a combo guard to share minutes with Conley and Mayo. The Grizzlies need to come away with someone who can play 35 minutes, whether by drafting Rubio or trading for a power forward. (No, Jason Thompson is not the power forward I have in mind.)