This post tests various embed blocks:
Posts that have media-related tests
Media: Twitter Embeds
Really cool to read through and find so much awesomeness added to WordPress 3.6 while I was gone. I should take three weeks off more often. — Andrew Nacin (@nacin) April 3, 2013 This post tests WordPress’ Twitter Embeds feature.
Edge Case: Many Categories
This post has many categories.