One of the most famous, or notorious, passions of Magic R&D head Mark Rosewater is getting a third silver-bordered joke set printed. Having accomplished a poison-counter block and put the word "double" on dozens of cards, all that really remains of his unrealized design interests are an Ooze lord, the return of Squirrels, and Un-set three, and that first one is due any block now. Recently, he's gotten a spate of questions about a finale to the purported "Un-block" on his Tumblr blog, and has answered them with unusually positive responses.
First off, when dalucaray asked him, "I tried making a fake Un- set for my friends to draft, and discovered I couldn't find much design space. Do you have any ideas for your currently hypothetical third Un-set?" he wrote:
I have many ideas. I’ve been coming up with cards from the day after I handed over Unhinged.
For those keeping track, this is at least eight years ago. Mark is known for his keen sense of humor and especial love of puns - keep in mind that he was the principal designer of an entire silver bordered set that never got published, that was to be titled Unglued 2 and released a couple of years after the original.
He was asked by eldritchguy, "What things beside a third Un set could be done in silver border?" and replied:
Anything that wasn’t tournament legal. Mostly it would have to be something that justifies it not just being black bordered. That could be either mechanically or flavorfully (or both) justified.
Now, reading into this answer - cards that were mechanically wacky enough to be illegal in tournaments but had flavor consistent with the rest of Magic would be off-puttingly strange; and cards that had Magic's ordinary mechanics but flavor so different as to be incompatible would be another IP altogether. Implicitly, this means that there is still space for the traditional Un-set, and silver-bordered sets are still under consideration. Further clarifying, when romanticjester asked, "Is a third silver bordered set more likely than a third Un set?" he said:
I believe if we do a third silver-bordered set it is more likely to be Un than not. The Un sets have a proven track record and an audience who wants it.
Rosewater is an Un-fan, but also is well aware that R&D has to sell a product - one of his favorite blocks of all time was Time Spiral and he nevertheless recognizes that something like that should never be done in a normal expansion again. If Mark Rosewater says that Un-sets have a proven track record (Both Unglued and Unhinged sold well, Unglued at a time when most Magic players would want to spend their money on the incredible power cards of Urza's block and Unhinged in the disillusionment of Kamigawa block, even, but both were overprinted), he means it.
Are you in favor of seeing a third silver-bordered set? Let me know in the comments.