Microsoft thinks they have something that will change the face of RTS with their new "Blitz" mode. Blitz is a RTS/Card Based mode that will be playable in the upcoming Halo Wars 2. The mode has players build decks of units, buffs, and vehicles beforehand and then pit them against in opponent in battle using the RTS style.
Essentially it's Deathmatch but without the building of units and your army relies on the draw of the cards and using a little bit of strategy. Of course, people are already screaming "MICROTRANSACTIONS?!" in the forums, but this mode isn't essential to the game. If you don't want to play it, play one of the many other modes the game will offer that will not use these cards in any way.
Money grubbing aside, the concept does sound interesting. Card based/RTS combat has a lot of potential and God forbid the RTS genre attempts to freshen things up for the first time ever. That said, this new mode essentially removes everything about an RTS and makes it "drop cards and watch them fight" which if done right is an entirely new thing.
When you add in special character abilities and deck building based off that character I see a lot of competitive potential for this game, even if it isn't wholly an RTS experience. If successful, I definitely see it becoming one of those things that finds it's way onto the esports circuit, which I'm guessing is the goal of Microsoft in adding this.
Even if the cards aren't free I'm eager to try this one out. It sounds like a cool concept that if executed well could create an entirely new subgenre. If you don't like it quit whining, it's only a fraction of the game that you can completely avoid if you so choose. If you looking for where they talk about the mode skip to 2:30.