A new item just popped up in the Play Store sidebar called My Play Activity. Once it's fully deployed, this will act as a list of all the Play Store content you have reviewed and shared. It's essentially the web-based version of the recent activity page in the updated Play Store app.

2014-04-01 17_03_16-Artem Russakovskii - Google Play

The pages are loading sporadically, but the change is probably still propagating. In fact, the link itself is only showing up sometimes. When everything is done, you should be able to access anyone's publicly shared Play Store activity (probably linked via Google+). The sidebar link will direct you to your own page, though.

You might have to refresh a few times to get your page to load. If the link isn't showing up in your sidebar yet, there's a URL below – just give it some time to completely roll out.

[My Play Activity]