First off Nvidia doesn't need to license Mantle, it is open source.
As mousemonkey noted...This is incorrect. Even if they did allow it, not sure NV could implement it without making GCN chips or at least slapping some of GCN on.
The bigger question is whether or not it is worth the premium for monitor manufacturers to adopt G-Sync, it is: proprietary to Nvdida (trust me they are probably not interested in licensing it for anything short of the keys to the gates of heaven) and also it adds to the cost of the monitor to the end user and unlike what some of the Tom's readers and forum members think the world is not filled with high end enthusiasts who will go out of their way to get supported hardware, the OEMs will put a graphics card in there and the consumer will take it and not care.
It only requires a 650TIboost or higher. That's just about the lowest end you can get, and as it gets integrated instead of a card replacing chips inside that are already there, cost will be lowered substantially (you don't have to pay for the chips the current retro-fit kit will be replacing). The scaler etc inside won't be needed, you'll just use NV chip instead with extra features.
I am not saying that G-Sync is useless but what I am saying is that Asus is the only manufacturer that has plans for integrating it into their monitors that I have heard of so far.
Incorrect, Viewsonic, Philips and BenQ are already on board with Asus (only a few left, samsung, lg, acer maybe a few others, they'll all join).
Also with DICE and AMD's partnership with Mantle it has huge marketing bump because they have a target market and by having a AAA game the size of BF4 launching with Mantle support people learn about Mantle and again think that if BF4 has it there just be something good otherwise such a big publisher and game wouldn't use it.
Dice got paid to use it. Physx is in all consoles, 65% of pc cards etc, many engines (unreal, unity etc)...But only 60 or so games have chosen to use it in what, 6-7 years?. Most of those do it on cpu also with help from gpu if any (Borderlands 2 is an exception, not the rule). Just because it's in an engine, it doesn't mean they have to do anything with it. Carmack, Sweeney, and Andersson were all pretty clear. They are not happy about more API's and you can easily get that they won't be using it without compensation. Carmack said right on stage they already have pretty close to metal with gpu extensions etc, he all but called it pointless. They all said you don't want to be writing for a bunch of different API's. Even Andersson said at most he hopes it inspires features globally not proprietary. It almost seemed he was trying to defend it a little due to AMD paying them, but it looked painful while he tried...ROFL. Pressed further he hoped it inspires other stuff, not he hoped to be using it daily. He didn't praise it and they make BF4
Gsync on the other hand, was praised by all 3 and many more, and all websites