"The June 2014 Standard arena rotation is now online. On the first Monday of each month, we will be cycling the Standard arena pool. Rather than only having access to the same standard arenas day in and day out, each month we will now feature 26 arenas selected as playable for Standard-level matches.
Newly released arenas will remain exclusive for at least three months, but every other arena is eligible to be included in the cycle."
Standard Map Pool:
Start date: June 2, 2014
End date: July 7, 2014
Base Siege
Beyond Reality
Blood Run
Campgrounds Intel
City Crossings
Cobalt Station
Cold War
Chemical Reaction
Double Impact
Dreadful Place
Electric Head
Focal Point
Foolish Legacy
Fuse
Future Crossings
Hell's Gate Redux
Jumpwerkz
Longest Yard
Monastery
Overkill
Retribution
Siberia
Skyward
Somewhat Damaged
Tornado
Wicked
Windsong Keep
Links: Official Announcement