Here's an unofficial changelog for leaked 10.2 [leaked version available at Crackberry]:
What's new in leaked OS 10.2
Performance
- Clearly improved system performance, application support (including Android Player) and animation
BlackBerry Hub
- New "Priority" with the ability to establishing automatic priority rules (For example, based on senders name…)
- Differentiation between priority messages in the hub (red bar on the right)
- Shortcut to a list of all attachments
Notifications
- New visual notification on the lock screen (just click on the notification icon to expand)
- The new "fast" actionable notification at the top of the screen (in any application) with the ability to respond and take action without running dedicated applications (mostly)
- A separate notification for each group of BBM
Home Screen
- A new quick settings menu with additional buttons and change of appearance
- Dedicated access icon for BlackBerry Hub
- New default wallpaper
System Applications
- Task Manager, which allows such check which applications are taxing your system and battery
- Weather app with a fresh look
- Native application Evernote
- New indicator for data
- Remember gets extensive improvements including a search option
- Changing some elements of the Music app’s UI
Default Applications
- Ability to select and / or change the default applications that run on certain activities / references
Relations
- Displays the total number of contacts
Phone
- You can send a predefined SMS when you reject a call
UI
- Simplification of many interface elements, improved buttons and sliders
Settings
- This finally is a native app. No more slow adobe AIR
- Change the look of some of the UI elements
Share
- A new screen with a preview of the file sharing
- Ability to edit photos directly from this screen before sending
Keyboard
- The different sounds of clicks for keys other than letters / numbers
- Vibration alerts can be activated by the introduction of an automatic change / amendment of the word
Clock
- More than one alarm – for the first time in BlackBerry OS, you can set more than one alarm at a time. Access to this feature can be accessed directly by an icon on the screen watch, which is located in the upper right corner.
Camera
- New shortcut to the location settings geolocation photos
- Preview transmitted images
- The camera can now turn on a grid
- After shooting, just drag its thumbnail in the top and then on one of the display in such case the – delete or share
Connections
- WiFi Direct
- New categories of tags NFC Smart Tags
Personalization
- Ability basic photo editing and to set as wallpaper
Voice Dialing
- Additional features for advanced voice dialing
Browser
- New loading bar browser
- Longer holding the "Back" button in your browser calls the abbreviated browsing history
- Reversible color reader mode (white text on a black background)
- The smaller top bar
Other
- New recordings instructional
- More instructions on the screen when you first start and configuration
- New information after a screenshot – the amount of free memory
- The new interface operations copy / paste
A lot of folks are going to want this as soon as it comes out, without delays, VZW 
