Two Macs and One Apple ID (purchases on App Store) I have a Macbook Air mid 2012 model and now I'm thinking about buying a Mac Mini or a iMac so that I can have my Macbook Air for when I'm on the road, and the Mini or iMac stationed at home all the time. For my setup now, I have a external display for my Air when I'm working at home, and I'm getting kinda tired of disconnecting and connecting the external display, mouse, and keyboard every day.

But then I thought about, how about all my purchases on App Store (OS X apps), are they automatically cleared to be installed on my new machine, while I still have them on my Macbook Air or is there going to be some kinda conflict with license?
This question can only really be answered on a per app level (The End User License Agreement (EULA) will specify how many machines an application can be installed on), but in general I have a MacBook Pro, My wife has a Macbook Air and we have a media center mac mini and I install all my apps on all of them without an issue, but we share a single Apple ID for all app store purchases, since apple has restrictions on using multiple Apple IDs on a single machine.

Developers seem to have a more sane point of view on mac (excluding Adobe or other graphics packages) than on windows, so I haven't had an issue.