As Developer, This is my Wish List for Android 5.0 / Key Lime Pie.
1. File Manager
2. Video Processing API like cut, copy, merge and effects.
3. Image processing, effects, drawing, etc.
4. Video Call with SIP API
5. Slide-in / Fly-in menu
6. Integrated social network like Facebook, twitter and linkedin.
7. Gallery with Multiple File Selection or multi type file selection.
8. Improve Data Backup API for easy cloud storage integration.
10. Document management API like open office, PDF, ms-office, etc.
11. Chips EditText i.e. Contact selection in Gmail
12. Staggered Grid View [http://www.androidviews.net/2013/01/pinterest-like-adapterview/]
13. Android Annotations [http://www.androidviews.net/2012/11/android-annotations/]
14. Color Picker Control
15. Validation Framework
16. Cards UI, like iOS has in PassBook app
17. Range SeekBar or double headed seek bar
18. Arc Menu - same as Path app
19. Chart API
20. Improvement in ADK - Accessories development kit API
21. Improvement in DRM - Digital Rights Management API
22. Storyboards tool for fast development i.e. http://www.raywenderlich.com/5138/beginning-storyboards-in-ios-5-part-1
23. Better Approach for Universal App development (Smartphone & Tablet)
24. Google Cloud Print API should be integrated in OS.