One of my home pages when I fire up IE each day is the Microsoft Download Centre filtered on the 30 most recent new downloads.
You get a fair bit of dry stuff in here like links to EMEA case study resources (surprisingly high download rate) but you also get a heads up on cool stuff like Device Simulator for Windows SideShow and Live Search Maps for Outlook. I've been harvesting links from the site for a while and often ping them to my own team to blog about but it's becoming too much work so I decided to share it with the world and get others to help shine a light on the nuggets. I suspect people like Mary Jo Foley already know about this site as she's always up to date with the latest downloads but I wanted to share it with everyone.
The site sort of has a crowdsourcing element to it already as you an filter on most popular downloads - predictably IE7 is at the top - but if the site had an API that allowed you to mash this stuff up and perhaps see most popular in the last 30 days or most popular for developers that would be very cool. Just a thought.
In the meantime, check out the page if you're a follower of Microsoft stuff as I suspect you'll find some cool stuff you never knew was there.