Looking ahead, we want to continue celebrating personal successes and milestones for all you dedicated Hearthstone players. Our next major update will introduce some really cool new portraits that you can earn by earning 1,000 wins with each class. Wins earned before this update goes live will retroactively count towards these totals. Take a look at a couple of examples below and start stacking up those wins!
Source: https://news.blizzard.com/en-us/hear...to-hearthstone
For one, I only have a class at over 600 wins (warrior) and everybody else is at 200-300.