I think the concept of both the OUYA and the GameStick (at intended endgame) is less a focus on emulators and ports, and more at providing a home developer market not seen since the days of the earliest personal computers. The Apple IIs, the Commodore 64s, the Spectrums, the Amstrads, the Amigas and the like.
These are both consoles anyone can develop a game for if they want - without having to pay for expensive DevKits, Certification and going through a lengthy approvals process (not to mention licensing fees) as found on other home consoles from the big three.
That, and it provides an easy way to develop for a single hardware configuration geared at the "gamer" (which consoles still provide) - rather than having to develop your game for multiple variants of smartphone or PC if funding is tight.
On the consumer level, the target is a lot more focussed. They're aiming at people who DON'T want to feel like they're "limited" to the image of casual, touch-screen only games that are found on tablets and smartphones (rightly or wrongly), while lying back on the couch where a keyboard and mouse setup just does not work. We're talking here about the Indie Gamer. The type of person who plays games designed purely for the XBLA/PlayStation Network/Steam crowd - where the experiences are perceived (rightly or wrongly) as soulless, corporate creations suffering from Franchise Syndrome or Sequeliits.
I guess you could say the console is for the "NerdCore Niche". There's certainly enough of them out there to provide a potential audience for smaller game projects that are geared to traditional gamepad controls if we go by the Kickstarter pages. That and I'm certain anyone who wants to invest in one of these console devices is not going to imagine the next Triple-A hardcore gamer game among the releases that are no doubt incoming. People buying these will be doing so (in the main) eyes wide open.
My concern, though, is that price wise you get a much better value for money proposition from the Quad Core Tegra SoC powered OUYA than the Dual Core, low-end, A9 ARM based SoC in the GameStick (which has to keep inside a heat and power envelope equivalent to a USB Memory Stick). I think the GameStick is going to find itself rapidly limited by the lack of a touchpad and its lack of power and functionality when compared to its $20 more expensive competitor, not to mention OUYA's mandate of Free2Play/Free2Try only being touted as THE selling point of the console and GameStick have yet to make a similar claim.