Complex sentence: Lead designer Jay Wilson said in a post on Battle.net that the PvP Arena system would arrive in a post-release patch; it would include multiple Arena maps with themed locations and layouts, PvP-centric achievements, and a quick and easy matchmaking system.
Split into simpler sentences: Lead designer Jay Wilson said in a post on Battle.net that the PvP Arena system will arrive in a post-release patch. Blizzard said the PvP patch will add multiple Arena maps with themed locations and layouts, PvP-centric achievements, and a quick and easy matchmaking system.