To sum everything up, this bloke, Jocken Kolbe, created this website, got an informal approval from the developers and charities to be part of it, and then launched it without warning anyone. Only some (two, I think) of the devs had signed a contract, and no charity did.
According to Jochen, they should be happy to be on board and stop complaining about legal stuff. He had some trouble with his country's justice some time ago, you can find more about that in one of the other threads here, listed further down.
As the site wasn't ready, the first buyers (I was one of them) got an invalid link to download the games, but that is sorted out now (I have the games I paid for). You can use the "resender" button on the site to get a new link.
Read this for more info : http://www.indiegames.com/blog/2010/05/givewhateveryouwant_indie_game.html
Here is a small interview with Jochen : http://www.computerandvideogames.com/article.php?id=248403&site=pcg
And another one, longer : http://sixtyfpsorbust.tumblr.com/post/635687639/give-whatever-you-want-controversy-an-interview-with
Here we have a video of Jochen, ewplaining the process that got him into trouble in the first place, in germany : http://www.youtube.com/watch?v=hxfmVnKdmw4
And also this post by Bob Came in Pieces developers : http://ludosity.com/2010/05/dont-give-whatever-you-want/
These threads may also help you judge the situation :
http://www.gog.com/en/forum/general/german_scammer_abusing_the_humble_indie_idea_please_help_with_warning/96
http://www.gog.com/en/forum/general/givewhateveryouwant_com_indie_games_casual_games_asf/107 (the first poster being Jochen himself)

Do you know WHY the last thread veered into a flame war?

It does look fishy indeed.
I'd advise that no one buys its until we can see clearer.

How did all this batshit insanity start from a couple of indie guys trying to do something nice and legit? Everyone takes advantage of everyone, I guess.

Great, we really needed a new thread about this crap. Thank you very much.

Could we please not make any more threads on this site?

OK, quit raging about it and it will disappear. Sorry for making it.

I read on IndieGames.com that people aren't getting their bundles after paying. They, too, seem to think this whole thing is fishy.

Jep, I also read on a German forum Paypal payers don't recieve any email except the Paypal confirmation.

In the interest of minimizing misinformation, I'll just mention that they have, in fact, updated their story. Now they say that people are actually receiving their bundles.

Well, as of now so far there are still people who aren't receiving anything. I'll leave this quote here in case people can't help themselves from buying something new.

How do I cancel my payment? The payment is listed as 'unclaimed', I don't want to give any money to this troll.

Ludosity have updated their statement:
'Seems to be working now:
If you want to buy Bob for a small amount, check this out: http://www.givewhateveryouwant.com/
This is a experiment like Humble Indie Bundle but they will also have deals with other stuff, such as music. Anyhow, this is a test from our side and if you find the deal interesting, give it a shot '
------
I said I'd paid and hadn't received any of the games and got this reply from the developer:
'Hey,
I tried the service myself and got to a download link, although the site doesn’t seem to be 100% stable yet. I could download all of the games (one giant zip) and run them. So the pack itself is not suspicious in any way.
Try the Resender-button at the top right corner to get your download link (at least that is what the button says it is doing).
And I hope that the money indeed go to charity and the devs involved and not to a troll…'

why GOG advertising this site on the front page ?

I see that aswell...WHAT THE HELL?!