With Journey into Nyx just having been released, previews for Vintage Masters, Conspiracy, and Magic 2015 on the horizon, and the true names of "Huey/Dewey/Louie" block (probably Khans of Tarkir, but who's counting at this point) to be announced a week from today, you'd think the last thing on anybody's mind in the Magic rumor community would be the 2015 fall large set - that is "Blood" of the "Blood/Sweat/Tears" block.
And yet an innocent question to Mark Rosewater on his Tumblr blog prompted a minor but surprisingly substantive revelation about that block. When uncledragi asked, "Can you tell us the playtest names of any cards you are currently excited about?" Mark responded:
Yes, I’m excited about three cards in Blood - Larry, Curly and Moe. : )
As all people of culture know, Larry Fine and Curly and Moe Howard were the most well-known lineup of the great comedy troupe The Three Stooges. The Stooges were always associated as a team and were best known for absurd physical gags, so the cards clearly are part of some sort of related three-card group, perhaps a vertical cycle, or something more like the Fifth Dawn Machinery, meant to form an infinite combo. As keithrhart87 wrote in the comments, "So they all work together to create wacky board states?"
This is probably the most plausible theory about these mysterious playtest cards so far, and since "Blood" has definitely been finalized, we know they're in the set for real - but we have more than a year to wait to find out their true versions.