As I revealed back in February, Windows Phone 8 will usher in a PC-free experience as part of its many changes. This will include the decoupling of Windows Phone from the Zune PC software, which was originally designed to support Zune devices and services that are disappearing as well. (Some of those services will be updated and Xbox branded going forward, however.)

But we don’t have to wait for Windows Phone 8 to see this happening, Microsoft says in a post to the Windows Phone Blog this week. The decoupling is starting soon.

It begins with the removal of Windows Phone Marketplace browsing from the Zune PC software. This means that, going forward, you will “only” be able to browse the Marketplace from its web interface or from your Windows Phone handset. But this isn’t a huge limitation. Today, most people browse the store and buy apps only from their phones. And even the web-based Marketplace is much more popular with users than the Zune PC software, Microsoft says.

“We like to focus our engineering efforts where they matter most, and your taps and clicks tell us that’s our phone and web stores,” Mazhar Mohammed writes in the post. “So starting today we began the process of removing the Windows Phone apps option from the Zune software.” (The Zune HD app store will remain open, since this is the only place the 17 Zune HD users can find these apps.)

If you were hoping to say goodbye to the Zune PC software’s implementation of the Windows Phone Marketplace, this is your last chance. That’s because the next time you run the software (and let’s face it, the only reason to use this dog is to sync your photos back to the PC or to sync other media), you’ll see the following message:

features_have_changed

(Contrary to the message, there’s nothing “new” to see. Just less.) So take one last peek. The Apps section of the Marketplace will look like this before you restart:

before

And then this after you restart the Zune PC software:

after

According to Microsoft, more changes are coming. Beginning “in the next few weeks,” you will need to be using a Windows Phone 7.5 (“Mango”) handset to download, or purchase apps from the Windows Phone Marketplace using the device. (Browsing will still work.) This means that non-upgraded pre-Mango handsets will no longer work. Why is this you ask?

“Marketplace now has over 80,000 apps overall and is available in 54 (soon to be 63) countries around the world,” Mohammed explains. “Requiring Windows Phone 7.5 is part of a larger effort aimed at improving Marketplace performance and security, and paving the way for even faster growth and more new features.”