I have heard no mention of the Gal Civ II style of mining stations at all. I believe that entire method of gathering resources is now superseded by the new way of planting a star base near some resources and it will now 'harvest' said resources ...all of them. 

I have not seen anything for asteroids. I would think that a star base will eventually harvest those somehow. 

I am patiently waiting to get off work so I can down load the new Alpha!

In Alpha 3, starbases can build a "mining ring"; an the tech tree lists additional modules for that (like mining barracks, ...), haven't figured that out completely though.