Google has announced its upcoming Android 1.5 Linux OS platform SDK, based on the cupcake branch. Some new features are the video recording option & extensive widget support.

User interface refinements

• System-wide:
  • Refinement of all core UI elements
  • Animated window transitions (off by default)
  • Accelerometer-based application rotations
• UI polish for:
  • In-call experience
  • Contacts, Call log, and Favorites
  • SMS & MMS
  • Browser
  • Gmail
  • Calendar
  • Email
  • Camera & Gallery
  • Application management

Performance improvements

• Faster Camera start-up and image capture
• Much faster acquisition of GPS location (powered by SUPL AGPS)
• Smoother page scrolling in Browser
• Speedier GMail conversation list scrolling

New features

• On-screen soft keyboard
  • Works in both portrait and landscape orientation
  • Support for user installation of 3rd party keyboards
  • User dictionary for custom words
• Home screen
  • Widgets
    • Bundled home screen widgets include: analog clock, calendar, music player, picture frame, and search
  • Live folders
• Camera & Gallery
  • Video recording
  • Video playback (MPEG-4 & 3GP formats)
• Bluetooth 
  • Stereo Bluetooth support (A2DP and AVCRP profiles)
  • Auto-pairing
  • Improved handsfree experience
• Browser
  • Updated with latest Webkit browser & Squirrelfish Javascript engines
  • Copy 'n paste in browser
  • Search within a page
  • User-selectable text-encoding
  • UI changes include:
    • Unified Go and Search box
    • Tabbed bookmarks/history/most-visited screen
• Contacts
  • Shows user picture for Favorites
  • Specific date/time stamp for events in call log
  • One-touch access to a contact card from call log event
• System
  • New Linux kernel (version 2.6.27)
  • SD card filesystem auto-checking and repair
  • SIM Application Toolkit 1.0
• Google applications
  • View Google Talk friends' status in Contacts, SMS, MMS, GMail, and Email applications
  • Batch actions such as archive, delete, and label on Gmail messages
  • Upload videos to Youtube
  • Upload photos on Picasa

New APIs and developer tools

• UI framework
  • Framework for easier background/UI thread interaction
  • New SlidingDrawer widget
  • Horizontal ScrollView widget
• Home Screen framework
  • APIs for creating secure home screen widgets
  • APIs for populating live folders with custom content
• Media framework
  • Raw audio recording and playback APIs
  • Interactive MIDI playback engine
  • Video recording APIs for developers (3GP format)
  • Video and photo sharing Intents
  • Media search Intent
• Input Method framework
  • Text prediction engine
  • Ability to provide downloadable IMEs to users
• Speech recognition framework
  • Support for using speech recognition libraries via Intent
• Misc API additions
  • LocationManager - Applications can get location change updates via Intent
  • WebView - Touch start/end/move/cancel DOM event support
  • SensorManager - redesigned sensor APIs
  • GLSurfaceView - convenience framework for creating OpenGL applications
  • Broadcast Intent for app update install succeeded - for smoother app upgrade experience
• Developer tools
  • Support for multiple versions of Android in a single SDK installation
  • Improved JUnit support in ADT
  • Easier application performance profiling

For developpers the Android 1.5 SDK preview is available here.