TheESO web-site likes to boast that ESO will be playable on windows or mac. I own a Macbook Air. Will ESO be playable on the Air, is it only meant for the standard Macbook?

Well like a PC it depends on the specifications of your MAC.

I have a Macbook Air 13 inch with i5, the 4000 gfx and 4 gb ram - it works.

(If this is NDA breach I'm sorry, please delete)

Im sure it will run on a macbook air, on low graphical settings. It should run on just about anything that is a proper desktop or laptop computer, just not stuff like tablets and very low-powered notebooks.

WHAT ARE THE MINIMUM SYSTEM REQUIREMENTS FOR THE ELDER SCROLLS ONLINE ON PC AND MAC?

[ The minimum system requirements for the game on PC are: ]

• — Operating System: Windows XP 32-bit
• — Processor: Dual Core 2.0GHz or equivalent processor
• — Memory: 2GB System RAM
• — Hard Disk Space: 60GB free HDD space
• — Video Card: DirectX 9.0 compliant video card with 512MB of RAM (NVIDIA? GeForce? 8800 / ATI Radeon? 2600 or better)
• — Sound: DirectX compatible sound card.

[ On Mac, the minimum system requirements are: ]

• — Operating System: Mac OS X 10.7.0 or later,
• — Processor: Intel? Core? 2 Duo,
• — Video Card: Intel? HD Graphics 4000, NVIDIA? GeForce? GT 330M or ATI Radeon? HD 6490M or better,
• — Memory: 4GB RAM,
• — Storage: 60GB,
• — Media: DVD-ROM,
• — Resolution: 1024 X 768 minimum display resolution.

** You will also need a persistent internet connection in order to play. Systemrequirements are subject to change over time.

https://help.elderscrollsonline.com/app/answers/detail/a_id/4720/kw/mac%20system