I do think Carlos Guillen will be the Tigers' second baseman next season. He is a much better player than Scott Sizemore or Will Rhymes. Those guys are there for insurance. Neither is, in my opinion, a long-term major leaguer. Sizemore has much more upside than Rhymes, though.
Big decisions are coming on Brandon Inge and Jhonny Peralta. The Tigers probably should keep both. That's not a bad left side of the infield. I wouldn't give Inge more than a one-year deal.
I'd try to re-sign Magglio Ordonez, but only for much less of a cost. And only for one year. I would not attempt to re-sign Johnny Damon. He is clearly on the downside of his career. Numbers this season reflect that. Inge is having a decent season - despite his critics. Peralta is a good player. Ordonez was a comeback player of the year candidate until he was hurt.
I still maintain the free agent the Tigers should be most interested in is Adam Dunn. They need power and run production - above all else.