I won't give a direct link but the Claw Recluse fansite does have a 64-bit setup.

That's good you don't give a link, we won't support piracy! :)

It is kind of weird, though, how Sega can normally publish the original Aliens vs Predator, even if it was also originally published by Fox Interactive.

Yes, Monolith has really quite an impressive portfolio of games, so I fully support this initiative.
In the order of preference I would welcome here mainly these titles:
- Captain Claw (this would be fantastic addition, clearly one of the best platformers of the 90s, and as was said, fans have already solved compatibility issues with Windows XP/7/8, even adding back multiplayer, which was missing in the original release!)
- NOLF 1+2 (very interesting half-stealth / half-FPS game, with a hillarious story making fun of all those spy films of 60s and 70s)
- Sanity: Aiken`s Atrtifact (mildly bizarre action game combined with the MtG-like card base system)

Anyway, as was already said, the main issue here is the complicated situation with most of their legacy IPs. I can imagine, that by some they don`t even know, who actually currently owns them.
But, I think there is always some hope - we have already Septerra Core and Gorky 17 here on GOG, and both games were distributed by Monolith, so that shows it should be somehow possible to get rights also for titles from their range.
edit: And I forgot about Blood 1+2 and Shogo - they are here too.

Even with the installation issue solved, Claw has low FPS on my Win 8 64-bit OS and doesn't run smoothly. :/

this may interest somebody here

http://www.gog.com/forum/general/no_one_lives_forever_trademarks_filed_by_night_dive_studios

Nice curio: Techland (Polish publisher and developer) was working on Claw 2 in 2007 and according to the news it was cancelled due to expiring rights for the title.

Gallery of cancelled Claw 2.

It was not completely cancelled. They just changed the game's title and replaced Claw with Nikita.

Nikita: The Mystery of the Hidden Treasure

! Thanks for clarifying that :) I'm glad it isn't Claw, game in motion looks terrible :P