What's good about it? Well, MRAM can have the speed of SRAM, but with the non-volatile characteristics of Flash. I am sure that the benefits of having something like that as system RAM in your machine are obvious (no more hibernation to hard disk, for one) but there are other benefits, such as the ability of the memory to withstand shock, magnetic fields and moderate amounts and posts low thermal and power consumption levels. But will it become the universal standard for memory? Clever industry boffins say no.
Why? Well, the doubts about MRAM are several, but one of the main is that MRAM may be much more difficult to commercialize than the people who are behind it thought it would be. And then there are other problems, such as those of expensive production of the memory and scaling issues, and the fact that the first generation of MRAM is well below the capacity of today's conventional RAM or Flash chips. All in all, the future of this technology is questionable. Yet again, we could see an excellent technology never reach consumers because of non-technical reasons, most of which have to do with profits. Kind of understandable, but a little sad.