News out of Auckland New Zealand is that the Acer M310 Mango phone made an appearance at Tech Ed 2011. The shiny black, beveled-edge M310, which is said to look similar to the Acer W4, has a meager 8GB of storage (unfortunately no images were available but we're still digging).
However, word has it that one thing that sets it apart from its other WP7 brethren is the addition of an HDMI output jack. This is an exciting feature in what otherwise sounds like a pretty basic phone. Another nice feature is that it will support DLNA over Wifi, which will allow it to communicate with other DLNA-equipped devices such as TVs, Xbox, etc.
Asus also had a unnamed handset on display at Tech Ed, which seemed to be an engineering sample, complete with "non-final code." The matte black Asus is worth a quick mention because it looked to have a front-facing camera, though that was not confirmed.
It's nice to see some new features popping up on new WP7 Mango phones. There has been a lot of news of where Windows Phone is headed with Skype integration and Xbox Live and features like HDMI and front-facing cameras will be key to bringing those thing to fruition.