Quotes from blogatog:
tarotbycharles asked: Would you be satisfied with a silver border solution to contraptions or does it have to be black border?
Silver border would be acceptable.
my-annoying-brain asked: Would you consider contraptions solved if they were done in silver border?
Yes. It’s a big enough challenge that I’ll use any and all available tools to solve it.
I am a little disappointed as well, but come on guys, he didn't have to actually give us contraptions at all. He didn't betray or deceive anyone. Also: Being silver-bordered doesn't mean that they will never appear in black border. It mostly just means that Maro thinks they aren't solvable in black border under the current rules, or don't make for a mechanic that could be used for a black bordered set. That attitude might still change in the future.
Also: I love crazy scientist world. I hope that there will be many in-jokes not related to only mad science though too.