In ArcCatalog 10.0 SP2 it is possible to display the Modified and Size column values, and to sort by them.
However, in the Catalog window of ArcMap 10.0 SP2, it is not possible to do this.
The reason I am looking for this behaviour is that I have a large number of MXD files in a folder and want to be able to use the Catalog window to locate, and switch between, any of the last 10-12 that have been modified. Without being able to sort them based on the Modified column (because it is not visible there), it is very cumbersome to scroll through them.
Please note that using the Recent maps list is of no use for this because the maps I want to access have been created by a Python script and not previously opened in ArcMap.