I believe the logic here to be very flawed.
There is likely no SoftMaker officesuite for WP7 because WP7 comes with Microsoft Office. How many people are going to by a non-market-leading competitor when the market leader comes for free?
There is no skype for WP7 because apparently Skype needs access to some lower-level apis which WP7 has not yet oppened up. http://forum.skype.com/index.php?showtopic=769383&st=60
It's an early platform, and what 'killer' productivity apps are available for other devices, with the exception of Skype?
When/if WP7 gets more traction (as a happy user, I believe it will), I'm sure there will be more 'sophisticated' apps.