Steam Loyalty Program and Summer Sale Dates Revealed?

A pair of tweets from Pavel Djundik have word from the Steam Database developer to expect the Steam summer sale to run from June 25th to July 9th (thanks VG247). His first tweet attributes this to "generally trustworthy" Chinese sources. The second tweet says this is "confirmed," which expresses his confidence in the news, but it is obviously not an official confirmation. But he's not done there, as in another tweet he says he's ferreted out Valve's plans for a loyalty reward system on Steam. This is likewise still a rumor, but here's what he says about that:
Valve is working on loyalty awards/rewards. It has a point system, and a system to add reactions to user reviews.

Also includes reward items, redeeming points for badge levels, and possiblity game discounts.