I think it's a matter of wait and see. As a result of Benson not taking part in camp last year, and effectively not taking part in the preseason this year, no one (on this site) really knows what Benson is capable of on an NFL level. A few reasons to expect him to end up the starter this year:
1). Jones didn't look great in the preseason... he may have been taking it easy, so as to not get hurt, it may have been the play calling, or it could be that his hammy is causing him more trouble than we know.
2). The Bears are cheap. They poured a LOT of money into Benson. They will want to get some return on that investment.
3). Thomas Jones has historically been somewhat injury prone. Last year he recovered quickly, and played through pain like an iron man. But what happens if he gets a more serious injury? What happens if he's just ineffective?
4). Before the injury, the reports were that Cedric has come a long way in his blocking, and has learned the playbook.
DEFINITELY doesn't mean Benson will be an effective RB. Definitely doesn't mean he's better than Jones. But I think we're going to see him plenty this year. I hope in some starting capacity... raises his FF value. But as a Bear fan, I just want whatever works.