Beer aging is definitely temperature dependent.
A beer will age fastest at room temperature, and slowest at near freezing. Most people who want to age a beer (or wine) would prefer a steady moderately cool temperature like in a cellar.
In the fridge, a keg will age very slowly as a rule so if I have a keg that is a bit young and it needs a bit of age, I'll keep it at room temperature for a week or so (or longer, depending on what it is) before putting it in the kegerator. Hoppy beers will start to lose aroma fairly fast, but some beers will not change much at all over the course of their life in the kegerator.