Having trouble getting the Windows Phone 7 dev tools?
If you’re trying to get to the https://developer.windowsphone.com/ site to download the developer tools (or for any other reason for that matter) but you’re seeing an error message, try this URL instead: https://developer.windowsphone.com/windows-phone-7/. That should tide you over until the homepage issue is resolved.
The current public version of the Windows Phone 7 developer tools is still the April CTP (Community Technology Preview) Refresh.