Evaluating Mobile OSes

My Windows Mobile 6 phone continues to perform erratically (rebooting itself now and then) although the battery life is now reasonable due to battery replacement.  So still wanting to replace it and then give my iPod Touch to my wife.  The article Mobile OS Showdown: Android, BlackBerry, iOS, and Windows Phone 7 provides several slants for comparing features of the mobile OSes.  Some criteria and considerations that sets the mobile OSes apart:

• Two-way sync with multiple Exchange-protocol (e.g. Google) calendars
• Customization, e.g. different virtual keyboard or home screen
• What security granularity and warnings when installing new app?
• SSL connection when connecting to retrieve email, calendar?
• Voice control of device and extent
• Turn-by-turn navigation 
• Important:  Does default browser support Flash?  HTML 5?
• How are email attachments handled?  Can choose application to open them?
• Open file system structure
• What formats can default media player handle?
• VoIP calling
• Multi-tasking for third-party apps? 
• OS-specific features:  WP7 Live Tiles and Android's Notification pane

The hardware of a particular mobile device is another story.

Some thoughts:

• Apps - is developing a WP7 app that integrates well with the OS so different compared to the other OSes that developers will avoid offering a WP7-version of their app?
• Office suite - how good is Android's native Google Docs app?  How well does it work offline? 
• iOS seems to marry data and application together, that is, data resides in one application and to access it, you have to use that application.  Another way of looking at it:  You can't choose which application to open a piece of data.  Generally this is not a problem which seems to be iOS's design philosophy