Making those mirrors may be half the battle. Just like with CO[sub]2[/sub] lasers, polished metal could be the mirror. Theoretically, anything is possible. All that's required is time and money for the research. But there isn't really a good use for an X-ray laser so why would people go through all the trouble to make something "cool" just for us, laser addicts?
Yeah, many people said "it would't work" to many things in the past, and they were wrong. Of course you wouldn't use normal mirrors, but I'm sure it will be possible.The reason why we're never going to have them in pointer style is that they would be EXTREMELY dangerous of course.
There was a time, way back in the day, where shoe stores used an x-ray gimmick so you could see your feet in your shoes to find the perfect fit or something lame like that. Guess how long that lasted :
Handheld x-ray lasers? It'll never happen for a lot of reasons, not the least of which being the very people that would actually want and use such a thing.