Top 10 improved capabilities in Lightroom 5 - they are:
1. New Full screen preview (F key, Shift+F key)
2. More options in Loupe Overlay
Lr 4.4 | |
Lr 5 |
3. More options in Create Smart collections
4. More Crop Overlays
...
For more see the video presentation of Lightroom guru Julieanne Kost: