Don't know much about XNA. But if you're looking for some easy high-level stuff with c# Unity is getting exteremely popular. So your alternative to XNA does not have to be C++ and Opengl.

XNA is still the only way to ship games on XBLIG for the 360.

Its still fully supported on WIndows Phone 7 and 8 - though on 8 you don't get access to any cool phone 8 features.

It runs perfectly well on Windows 8 too though you cannot make an XNA app that will run in the windows app store. Desktop mode only

Steam fully support XNA (guncraft is 100% XNA and we just shipped on steam) - they auto install XNA3 or XNA 4 and there's several places you can get managed wrappers for the steam APIs we use this one http://www.communityexpresssdk.com/ - its been good for us and the team has been very responsive

If you are learning to make games and you don't want to go the designer engine route (like unity) then XNA is one if the best ways to learn the principles.

Saying all of that Microsoft have not touched XNA for several years now and there's no plans that anyone knows of to start it back up.

So no news on Xbox One support (though Mono.Game will support it if possible), you really can't ship in windows 8 store and who knows about future phone releases. I'd say XNAs time as a platform to ship games is coming to an end. If you can ship on steam I'm sure they will support it for a while yet but I wouldn't be starting any long term (1+ year) projects unless you make sure that your code also compiles in Mono.Game

As Andy states, the dream of XNA is far from dev and it's still supported / taught across the world, Microsoft just choose to not acknowledge it for the moment (it's a bit like VB and that still seems to linger)

Its spirit still lives on in projects like MonoGame which is constantly evolving past the boundaries that XNA originally had including DX 11 and multi-platform support (now supports, WP 8, Win 8, Mac, iOS, Android, Ouya, PSM, Linux and likely more in the future)

Alternatively if you want an engine, then the SunBurn gaming engine from synapse gaming is still heavily XNA based and they recently re-engineered the XNA platform for their multi-platform offering which you can use with or without the Engine (pure XNA or XNA on steroids)