First Impressions:

The only way I was able to access the BC games was through the Preview App. In the app there is a Quest for Backwards Compatibility. In that quest you will get a list of the games you have digital rights to:

I chose to download Alien Hominid HD. XBL is slow ATM and I was lucky to be able to get through and download a game. After the download, I launched the game. At first launch a Virtual 360 gets installed on your Xbone. It was taking a while to get all the 360 info that it needed, so I decided to see if the Achievements app worked with it. It was available as an option when launching the game. It didn't seem to work, perhaps not implemented yet.

Decided to watch some TV while waiting instead:

Once the game started, it was smooth sailing. Game ran beautifully and might even look better than on 360. Even friends notifications pop up. Don't know how to check them though.

After the intial install, the game loaded up quick once launched.

Because they had no choice, the PS3 was being run into the ground, and they needed to get back onto their feet.

That's great! Hopefully it runs like you say!

I'm hoping Alan Wake is one of the first 100 games when it is available to everyone.

They should focus on exclusives first and Arcade games (when indy and Arcade games didn't matter) then they should add the multiplats...

For know it's still a speculation how the emulator works, but if it's work then it's also be posible for PS4 do the same thing on software level, only the different is it will take much more work for SONY to make PS3 runs on PS4, because the Cell is literally more advance then Xbox 360 3 core Power PC CPU. For know i only have to wait and see how the things work on Xbox One. 

Wow, I am really impressed! They seem to really use an emulator (other techniques would require much more work) as hinted here: http://www.neogaf.com/forum/showpost.php?p=168068069&postcount=1780
I don't know how but I guess we get a false image on emulation because we mostly only know homebrew emulators. If IBM did a ppc-x64-emulator it seems it can be leagues better because they know better than no one how the chip works. I guess the load is pretty heavy on the Xbone and let's see how demanding games will perform with this solution.
PS3 emulation on PS4 is a different story - the PS3 has too many cores you would have to emulate. Even by 1:1 matching the cores it wouldn't be enough as the PS3 has 7 in total but only 6 available for gaming purposes, not to mention that you have the PPU as ppc and the SPUs with cell with their own dedicated isa which is way more similar to a GPU than a CPU. There won't be enough power.

To me it is a big deal as I have a lot of digital games on 360 which makes the transition even easier and ensures I am able to play the games even if MS stops selling the 360 and mine dies. Not to mention the convenience factor playing all of your Xbox games on one system.

Also I don't see why you are using XOR - this is good and new games are also good. If it's a big thing depends on how *you* see it. You obviously don't, for your own reasons.

Yeah, but why? Console was way too expensive and look at how well remasters of games sell. Look how PS classics sell to other systems like the PSP, VITA and so on. So don't tell us there is no demand in playing old games. I've read enough on this forum to see people thinking how big PSNow is and how many people wanted titles as classics on their systems. Not to mention that many buy games twice this way.

I don't think that will be possible on PS4, to be honest. The Cell is extremely complex and wasn't there a graphic that claimed that it's even more powerful than the CPU of PS4? Nah, I don't think PS4 will get it. And even beside of the technical aspect, that would hurt PS Now and Sony won't want that.

I guess MS is lucky that the CPU of 360 was much simpler. It's a great feature, I'm very much looking forward to this. I hope they add Red Dead Redemption at some point since I've never played that one.