Mark Rosewater's Tumblr blog has become something of a rallying point for amateur Magic card designers and proponents of game design of all stripes, as Rosewater candidly discusses the difficulties and challenges R&D's design teams encounter. Among the specific problems that often come up and that have yet to be definitively solved: Expansion of red's portion of the color pie, trimming blue's overlarge bag of tricks while also giving it a real combat mechanic, and more specifically one it might share with red, and making sure green and white feel more distinct from one another in both flavor and function.
Already, Blogatog has led to red getting forms of card draw like looting and the Elkin Bottle mechanic, but there are still other looming issues. But there might not be for long - When doopboopdoop asked Rosewater, "Out of all the long term design challenges (like mechanics for red, separating green-white, etc.) which one have you made the most progress on?" he replied:
You’ll see in two years. : )
We have made a bunch of progress, by the way.
Given that R&D works with a two-year lead time, this means the block that is currently being designed and refined by R&D has a solution to these issues that may wind up becoming consistent. Given that the blue combat mechanic is the most pressing, and also the most directly solvable of the problems (it simply entails coming up with one keyword or nonkeyworded piece of text), that is presumably what he means, but it's hard to tell. Regardless, Rosewater's optimism is infectious, and often, pardon the pun, right on the mark.