Microsoft just sent a note to MSN Direct Smart Watch owners. If you update to Windows Live Messenger 9.0 (just hitting beta, but won’t go final until February), you will lose the ability to send messages to your Smart Watch.

In case you didn’t know, Microsoft’s abandoned-but-still-supported Smart Watch platform had has a feature, which, for $20 per year, lets users receive MSN/Windows Live Messenger messages onto their watches. You could get notes from friends, or even message yourself, in unlimited fashion.

In the email, Microsoft notes that they aren’t killing off the feature (yet), you simply need to stay with Messenger 8.5 or earlier on your PC.

Now that I live in a reliable MSN Direct coverage area, I really feel bad that the technology didn’t take off in watches. Cell phone watches are still years off from really being viable (and even then, folks aren’t going to want to use them… mostly). Getting constantly-updated news, weather, sports, stocks, and messaging on the watch was brilliant. And, unfortunately, Microsoft is in a unique position to deliver… carrying both a compact framework for the watch to run on (SPOT) and radio technology (via the MSN Direct network).

And, let’s be honest… MSN Direct for Windows Mobile is nice, but still very immature. It takes much longer to pull up data on a Windows Mobile phone than the Smart Watch. I hope that Windows Mobile 7 integrates MSN Direct service fully into the today screen (the Today Plug-in that is there right now, is a joke).