Yes, but it won't automagically make a blog for them. If that's where you want to go you'll need to check out the autoblog plugin available via http://plugins.b2evolution.net/ .

BTW why do you reference blog.de as if it was a b2evolution application? IF it is they've gone to great measure to remove all credit for the free software they're using. It looks like a b2evolution installation though. If it is then it is completely okay for them to remove all recognition of the development team, but I sure hope you don't do the same thing. Everyone is free to remove the crediting links and comments in the code, but it's completely rude.

Well, I wouldn't do so. I was just curious if it was a out of the box solution they run or if they have modified it a lot? Basically the signup process is important to me.

I saw it looked like b2evolution and later also that they wrote some credits here:
http://www.blog.de/srv/company/company.php?p=aboutus

It looks to me like they modified it a heck of a lot. The autoblog plugin gives new users a new blog automagically, but in that installation it looks like the new user also gets to pick a skin, and possibly even create their own. I don't think autoblog can do that, but I've never used it so don't quote me on that.

b2evolution is really made to be "your" blog with the option of allowing others to register and, at your discretion, post in whatever blog(s) you give them permission to post in. Some people use registration as a way to slow down comment spam - a "registration required to comment" type of thing. Others use it for a collaborative project type of thing - many authors in one blog. Then there's the thing where a group of friends all have blogs on one installation. The place some people want to go, and I suspect this might be you, is where anyone and their brother can start blogging as soon as they register. This last model is pretty far outside what the developers had in mind when they started this project, but autoblog makes it very possible.

Thanks for taking your time to answer my questions!