MLG operates MLG.tv, the #1 online broadcast network for professional level competitive gaming; the MLG Pro Circuit, the longest-running eSports league in North America; and GameBattles, the largest cross platform online gaming tournament system with 9 million registered users across the globe.
Keeping the Surface Connect port and making the Surface Dock compatible with the Surface Pro 3 in the process instead of replacing it with a symmetrical and reversible USB-C port is a tradeoff I posit Microsoft thinks is worthwhile at this stage.
To use a USB mouse, just plug it into the USB port on your Surface. To use a Bluetooth mouse, see the Add a Bluetooth device section in this guide. Pen Surface Pen included with Surface Pro Surface Pro includes a digital pen that you can use to write on the touchscreen.