This one is big news: Microsoft is dropping its in-house blogging platform for Windows Live Spaces and is switching to WordPress.

The news, from WordPress:

We’re excited to announce that WordPress.com is now the default blogging platform for Windows Live Spaces users. We’ve worked with our partners at Microsoft to create a simple migration service for Spaces bloggers to easily bring all their posts, comments, and photos to WordPress.com.

Over a six month period, beginning today, Windows Live Spaces users will have the option to move their blogs to WordPress.com. To make this possible, we’ve created a brand new importer for Windows Live Spaces to WordPress.com. New Windows Live users will also be offered a WordPress.com blog when they choose to create a new blog.

As part of this project, we’ve added support for Messenger Connect as a Publicize option, which enables you to automatically share updates to your WordPress.com blog with your friends who use Windows Live Messenger.

And from Microsoft:

As we looked at how we brought Windows Live and WordPress.com together, there were three big things we wanted to deliver:

  • Giving existing Windows Live Spaces customers an easy upgrade of their blogging experience to WordPress.com
  • Letting anyone connect their WordPress.com blog to Messenger so their Messenger friends are updated when they publish a new post on WordPress.com
  • Allowing Windows Live customers to easily create new blogs on WordPress.com
Upgrading a Windows Live Spaces blog to WordPress.com

There are 30 million people who are actively using Windows Live Spaces and have been eagerly awaiting the next set of new blogging features. For these customers, Windows Live and WordPress.com have worked together to build a simple way to move your blog posts, comments, and integrated photos right over to WordPress.com and start taking advantage of all their new features. And we’ll also redirect all your old Spaces URLs to your new blog, so you don’t lose any visitors along the way. If you want to get started today, just visit your existing Space and you’ll see a prompt.

If you’re not ready to migrate today, you can also choose to download your blog content, migrate later, or delete your Space.

Wow.

WordPress, coincidentally, is what I use for my Windows Phone Secrets blog. I wish I could use it here: Community Server is terrible.