In case you missed it, Apple has a brand new, thin laptop. It looks compact and elegant but has a new type of USB port. The USB Type-C port can be used for charging, transferring data, and as a video-out port. Technically, it supports data transfer speeds of 10 Gbps (though Apple suggests the max speed is a bit lower on these MacBooks). With a new port, you will have new adapters to deal with. Apple already has USB-C VGA Multiport and USB-C Digital AV Multiport adapters for you to get.
These adapters let you connect your MacBook with USB-C port to a VGA or HDMI display. You will also be able to connect a USB device and a charging cable. The bad news? These adapters set you back $79 each.