User blog comment:LoveWaffle/Quicksilver, Scarlet Witch, and Hulkbuster Concept Art for Avengers 2!/@comment-24751588-20140320001324/@comment-1895174-20140320202210

That's very possibly the case. Whedon said that the two don't start out as friends of the Avengers.

I've also heard people theorizing that Scarlet Witch and Quicksilver will be the MCU's take on Andrea and Andreas von Strucker. That could work, right?