The Surface 2 is what happened to the Surface RT. Microsoft decided that "RT" has no place on this product except, of course, its software ("Windows RT") because they painted themselves into a corner on that one. The message is something like, "It's Windows RT 8.1 but not Windows 8.1; in fact, you cannot run that software on it". I expect, and you probably know I have voiced, that this all is a moot point in the semi-near future (and that sucks).
Microsoft's "Official" Surface 2 overviews.
Paul Thurrott down at his Supersite for Windows reviewed Surface 2 in terms of the original Surface RT. The inclusion of Tegra 4 was a major plus for him yielding "night and day" improvement over the previous Tegra 3. In fact, he thinks that everything is at least as good as the original. There is not a single point on his rubric where the Surface RT beats its successor.
Of course there is a single section where the Surface 2 lacks (it is shared with the Surface RT and I think you can guess what it is). The ecosystem, apps for Windows RT, is the platform's "Achilles Heel". It is better than it once was, with the inclusion of apps like Facebook, but glaring omissions will drive people away. He makes this point almost in passing but I, of course, believe this is a key issue.
It is absolutely lacking in key apps, and you will most likely never see such crucial solutions as full Photoshop, iTunes, or Google Chrome on this platform. But if we're being honest with ourselves here, as we must, these apps are, for better or worse, important. (The addition of Chrome alone would be a huge win for both Windows RT and Surface 2.)
You are paying Microsoft to not let you install third party browsers. Literally.
Not only does this limit its usefulness but it also reduces the pressure to continue innovation. Why add developer features to Internet Explorer when you can control their use with Windows Store? Sure, Internet Explorer has been on a great trajectory since IE9. I would say that versions 10 and especially 11 could be considered "top 3" contenders as app platforms.
The other alternative is the web, and this is where Internet Explorer 11 plays such a crucial role. While many tier-one online services—Spotify, Pandora, Amazon Cloud Player and Prime Video, and so on—are lacking native Windows RT aps, the web interfaces (should) work fine, and IE 11 is evolving into a full-featured web app platform that should present a reasonable compromise for those users.
Only if Microsoft continues their effort. No-one else is allowed to.
Now that I expanded that point, be sure to check out the rest of Paul Thurrott's review. He broke his review down into sections, big and small, and stuck his opinion wherever he could. Also check out his preview of the Nokia Lumia 2520 to see whether that (if either device) is worth waiting for.