The evolution of Twitter on your Windows Phone continues with the most recent change being how the 'via' appears. We started with tweets from our Windows Phones as being referenced as "via Windows Live". Then Twitter become more tightly integrated with our People Hub.
About that same time the "via Windows Live" was changed to "via Microsoft". Now today, if you'll notice, the via has changed yet again.
Not sure when the switch was thrown but now tweets from your Windows Phone will be tagged as "via Windows Phone".
Now the "via Windows Phone will only appear when you tweet from your "Me" tile. If you tweet from Twabbit, glƏƏk!, or any of the other Twitter clients the tag will be "via Twabbit" or "via glƏƏk!". Even the Twitter app will tag tweets "via Twitter for Windows Phone". I wonder if we'll eventually see "via Surface".
Thanks, Jarrod, for the tip!