Windows Weekly tip of the week: Understanding the difference between Microsoft's email services and Microsoft's email applications. It's all about consolidation, and a single view into multiple inboxes. (Universal unread mail, basically.) Sometimes a native email client does make sense.
Windows 7 app pick: Raw support for Windows 7 and Windows Photo Gallery
Windows Phone 7 app pick: Windows Phone 7.5 RC. You must be a registered developer, but it's a great way to get a near-final version of the next Windows Phone today.
Mobile app pick #1: Windows Live Mesh for Mac OS X. If you use PCs and Macs, this is a great way to share folders between them.
Mobile app pick #2: OneNote Mobile 1.2 for iPhone. New version of OneNote, with some international availability. Still no iPad version though.