i needed to use Adminimize Multisite, preferably with the option to switch between global (network-wide) or site-specific settings, so i hacked it.
You can download it here: Adminimize Multisite
Specifically i changed the following files (relative to plugin directory):
By the default new blogs "should" use the network-wide settings, but that doesn't quite work yet and is something that I'm going to look into.
The only downside is that you can't set the network-wide settings from the network admin panel, but if someone wants to look at it and maybe even wants to use it, be my guest.
@Bueltge: maybe you can use this to add (almost) full multisite support