According to this article on The Hollywood Reporter's website, McTiernan has only served now one month of his year long prison sentence. Depending on how quickly the studio wants to get started on DIE HARD 6, which would depend on how successful it is, McTiernan could be available assuming they're not looking at a very quick turnaround.
Geez, really? This whole thing kicked off before the last Die Hard came out! The wheels of justice really do grind slowly!
Come to think of it, I haven't bothered to see the one before this. What do they say about dead horses...
And what will someone inevitably say about that on a James Bond site? Tedious, perhaps, but with some merit; there's no reason they couldn't make an entertaining fifth John McClane film; they just didn't.
As for John Moore, he's made five big budget films over the last twelve years, all with Fox; he first four have probably all turned a profit by now, but certainly weren't blockbusters, and definitely weren't critical successes or big crowdpleaser. Yet they seem to keep hiring him and he also seemed to get an early look in other projects over the years like Wolverine and such, I guess the guys at Fox just like hanging around the guy. Either that or he's a good "yes man"