If you have a laptop I prefer using the keyboard rather than the track pad for ergonomic reasons.
For instance, while browsing album covers I would like the cover to the right of the current one be selected when I press right arrow, down when I press down arrow and so on. Enter would open the selected album and select the first track. Up/down arrow would select the tracks and Enter would either add it to the current playlist or start playing immediately. Perhaps Shift-Enter would take care of the other one, and Tab or something would give you the popup menu.
For me this would make browsing much easier and more comfortable on a laptop.