"Arena battles and Rated Battlegrounds are only available during an active player versus player combat season. Season nine will begin on December 14th, so be prepared at that time to take your shot at glory!"
We are currently planning to end Arena Season 8 as early as October 12. At that point we will go through our normal process to determine who is eligible for the end-of-season rewards. This process should take approximately one week. It's very important for players who feel that they may be eligible for the Arena-specific titles and/or the Wrathful Gladiator’s Frostwyrm to refrain from transferring their characters to another realm or faction until after Arena Season 8 ends.
The next Arena Season will begin for level-85 players approximately one week after the official launch of World of Warcraft: Cataclysm. During the break between seasons, all rated matches will be turned off and Arenas will be unavailable. All Team Ratings, Personal Rating, and Arena Points will be wiped when Arena Season 9 begins, but Matchmaking Rating and Honor Points converted to the new currency system will remain.