Can't say I've seen a Coming Soon section anywhere around here. Nearest as I can gather, people make guesses, sometimes educated guesses but most often the releases are a surprise. For example, Jade Empire the other day threw a whole lot of people for a loop.
Also, there's a "vote for" topic somewhere in the depths of this forum where you can make the case for certain games you'd like to see here. Perhaps someone else will link that for you.

More than a topic, a virtual magic lantern :

https://secure.gog.com/wishlist

Rent a Hero was not released on PC, heck, it wasn't even released outside Japan (there is a US Xbox version, but Sega never released it). It'll never come.

Well.. it is always depending on the one who owns the rights for the game. Usually people here tracked the one who holds the right. In your case who owns the IP rights for The Movies, and made guess based on the possibility it will be released here. I think some publishers considered as almost impossible to release some of their games here. But who knows ?

For the Rent a Hero... that was a Dreamcast game ? I know that some Dreamcast games have been ported to PC. But I don't know about that one.

It was ported to PC. My Brother has a copy of it. It was ported to PC

This Rent a Hero, I presume?
http://www.mobygames.com/game/windows/rent-a-hero

I was thinking about this Rent a Hero:

http://www.mobygames.com/game/rent-a-hero-no-1

Which was only released on the Dreamcast and Xbox. I was thinking of the one made by Sega. I didn't know there was another game by the same name.

Yes there was a PC version Made It was release in DEC of 1999. Here is the link:
http://www.ign.com/games/rent-a-hero/pc-13227