A post on Battle.net has word from Blizzard that they have now implemented some of the changes to Heroes of the Storm matchmaking they recently outlined. Here's word on how placement matches in the MOBA should do a better job of evaluating players' level of competition:

We’ve just finished deploying several changes that we mentioned in our recent Placement and Ranking System Update blog:

• With today’s update, we’ve made improvements for placement in the mid to lower ranks, which should result in less conservative placements for players in this range.
• Additionally, we’ve added bonus points (extra points earned for wins when your matchmaking rating is higher than your current rank) back to ranks 5 – 1, so that highly rated players can more easily return to their proper rankings.

These changes are now live for all regions around the world. As always, we’ll keep an eye on how each affects Ranked play, and will make further adjustments if necessary. Keep sending feedback our way as we continue to make improvements for Ranked play in the future.