Microsoft has not yet put up for all and sundry to see just what is new in the latest firmware release, although knowing the way that they do things, they should have it up and running in due time, of course. Still, there does not seem to be any harm in updating your respective devices to the latest firmware, it is always the correct thing to do in the first place, although some users have run into the roadblock known as 0x80246013.
Hence, it would be prudent always to ensure that you have a backup made of your latest data and information on your tablet before proceeding with any kind of firmware updates. You can head on to the Surface Pro 3 update history as well as the official download page for all things Surface.