According to Neowin, Microsoft has begun pushing out Windows Phone 7740. Current "Mango" release is of course 7720 making this a minor but still interesting update to the OS. Not to mention a completely unexpected and unannounced OS update. According to the changelog, it fixes two issues

Exchange 2003 email support -- an issue we first reported and verified here at WPCentral

Voicemail notification issues

Of course the one everyone wants is a fix for the disappearing keyboard issue, but alas that seems to have escaped this update.

The big question though is who is getting this and when? Neowin does not mention which device or devices are slated to get this and the Windows Phone Blog is quiet on the matter. We just checked our HTC Titan, Radar and Samsung Focus S and have not noticed any updates. Commenters at Neowin are also not received this.

So until we get some confirmation, we're going to hesitantly put this under rumor, even though it seems like a legit and reasonable update.

Update: Kane Gao letus know that a fellow LG Optimus user in China is running 7740. Anyone else?

Thanks, Tim S., for the tip!