Are those games fun? they look good in some ways, but dated graphics and cheesy in other screenshots. I have never seen the game played in front of me to tell.

Uh, what did I miss? Is a new King's Quest really coming? Hadn't heared anything of it since Telltale dropped the reboot.

Is this in any way linked to the recent exhumation of Sierra?

King's Quest is excellent if you like adventure games. The first one has a VGA point and click remake if the older graphics and parser interface bother you. Sierra adventure games are enjoyable and most importantly death is integral. Actually, sometimes seeing how you can die is one of the most enjoyable aspects. Personally, I prefer Space Quest. However, if you are looking for some adventure games and have never played, they are definitely worth a look.

It's by Odd Gentlemen, developers of Winterbottom.
Also yes, King's Quest are worth a play, I played them all, I love this franchise.
You can try some KQ for free here, in their enhanced versions:

http://www.agdinteractive.com/games/games.html

There is some interesting ongoing discussion about KQ games in SpaceQuest forums.

http://www.spacequest.net/index.php/topic/826-is-it-worth-playing/

Basically, I'd recommend KQ 1-3 as historical curiosities. Not that I don't claim you can't enjoy them, but if you aren't familiar with the series that's way I'd recommend you to look at them on the first playthrough at least, keeping in mind how much in infancy the games still were and how grounbreaking stuff KQ games were during their time.

Ah yes, thank you.

Well, some classic Sierra going on here: http://blog.theoddgentlemen.com/

They are quite fun, if you're into this sort of thing. The original King's Quest is generally considered to be the very first graphic adventure, so it basically created an entire sub-genre.
These games sometimes have... questionable puzzles, but the entire series has a very, very charming atmosphere about it. This mostly stems from the fact that it largely draws elements from fairy tales and mashes them together in various ways. Yes, this often gets a bit cheesy, but mostly intentionally so.
Not all of the King's Quest titles are good, but several of them are very entertaining.

For a very good overview about the good and the bad in this series, I can recommend this video retrospective.

Sigh, such great childhood memories playing those games. I'm super excited to see what they've done.