Maybe it is just me but that is not how I interpreted that rumor at all...
If you read the original rumor from 9to5mac they mention a new multi-tasking UI that will in some way resemble the multi-tasking UI built into iOS (not sure if that is a good thing but windows management in OS X could use some work so I'm glad they are thinking about it)
Completely separate is the 2nd part of the rumor suggesting that there may be the ability to pause background apps. I don't think Apple is stupid enough to pause every app in the background even if you are using it. This will likely be restricted to new or updated apps anyway because I would imagine the developers will need to enable something like this. And in many cases it would be nice to have my laptop run as if the only thing I am using is the browser even though I have 20+ other apps/windows open so I don't run down the battery so fast. I'm not a huge fan of iOSification (hate it actually) but if you stop thinking about iOS and just think about how this might be useful for a laptop it doesn't actually sound like that bad of an idea depending on how it is implemented.
Personally I'm really excited to see what Apple comes out with in the next few months (for both OS X and iOS). I think it is the first time in a long time that I have no idea what to expect.
