If the Reds wanted an impact player at 3b (or, heck, anywhere in the IF), they should have dealt for Rolen.
Add me to the list of folks concerned about Aaron Boone in the pivot over 162 games given his history of injuries.
And if the Reds are going with an IF defense of Larson/Branyan(3b), Larkin (SS), Boone (2B), and Casey (1B), I think it becomes imperative to keep LaRue's arm behind the plate. As long as Larkin stays healthy, he'll be able to get by with his positioning, etc. But Larson, Branyan & Casey aren't exactly fleet of foot, and Boone will have a lot of ground to cover at a new position. Look for more balls scooting through the IF, resulting in more opposing base runners...