According to Blue Poster Eyonix, Arena season 4 starts on June 24th! Save your points! All personal and team ratings will be changed to 1500 for a fresh start. Season 1 gear will no longer be available from the Honor vendor (but will still be available from the Shattered Sun vendor for Tier 4 tokens), and Season 2 gear will take its place. Season 3 gear will now have lower personal rating requirement, and lower cost.
The first couple of days after new arena gear comes out, there is a big push for enchanting, and other item enhancement goods (armor kits being one). So if you have some extra stuff lying around, might be a good idea to put it up on the AH the evening of the 24th.