Mysterious Badge (Steam Summer Sale)

Check your badge pages!!!! I am assuming this "Mysterious Badge" is for the cards for the summer sale. Let the hype begin. I honestly am going in without a wish list. I'm just excited to see the sales and impulse buy. What about you guys? Also what are your guesses about the event? Will the cards/badges be used?

*Edit marnaish has supplied a link that may help with your card sets. I have personally never used it but I thought it put the link up here if any of you would to take advantage of it. http://www.steamtradematcher.com/tools/fullsets

**Edit this is just a reminder since it has come up a bit. If you buy cards off the market to create a badge and have not waited the week period to be able to trade them, the mysterious card drop that you get will have the same time lock on it as well.

***Edit this is a notification to those who do not know yet and a reminder to those who do. The sale is starting on June 11th

****Edit sviat has supplied a link so you can see the cards themselves with their prices and I believe the badge as well once it is craftable. http://www.steamcardexchange.net/index.php?gamepage-appid-368020