1) memory card thumbnail review (with tick boxes)
2) import only ticked files (repeat step 1 and 2 as necessary)
3) easy review to delete 'duffers' or grade 'keepers'
4) easy bulk grouping, tagging, keywording, etc.
5) filter for highest graded
6) work on those and save as psd/tif or jpg
7) easy access to that version history
8a) easy searchability to find an image (using date, tags, keywords, etc.)
8b) even if on an external HDD (or DVD?) that isn't in the computer at the time
do most of that, except possibly 8b which I think LR can.