The select command has two new options in AutoCAD 2007:
SUbobjects - like holding down ctrl key: selects faces, etc, on 3D models.
Objects - exits SU mode.
(The CLass option appears only when ARx objects are in the drawing.)
When you hold down the ctrl key to select parts of 3D models, AutoCAD 2007 has new markers:
* Selected edge -- marker is a short line.
* Selected face -- marker is an oval.
* Selected vertex -- marker is a dot.
Nothing to do with selection, but the -insert and minsert commands have lost the p-options from the prompts in AutoCAD 2007. The options, such as Pscale, are still there, just not displayed at the command prompt.
One more little item: F6 now toggles Dynamic UCS; prior to AutoCAD 2007, it toggled the coordinate display.