3dscapture.com

Just another feature request: what's about 3D support? Loopy already had this in a BETA software.

This probably won't happen. I just don't have the hardware to do 3D, so I could not test this. Plus, I have no idea how to do it implementation-wise. *Maybe* I'll have a look once the more important things do work, because I'm curious about how it could be done, but don't except that to happen soon.
In other news: Life seems to be slowing down again, so I might just find the time to *finally* continue work on C3C. Let's hope I'm not misjudging.

Did anyone ever get this running on a any version of Raspberry Pi? If so, under what distro and how well did it run?

There is a PKBUILD for arch linux, which has been released yesterday. You can find it under over here: https://bitbucket.org/snippets/lithm/ngXnA
If have never tried running C3C on a Pi, but you could give it a try. C3C itself should be no problem, but I don't know, if the libraries needed do run on the Pis architecture.
[EDIT:] Also, I finally overcome my illness and may be able to get to work with the binary builds again. At least I hope so. (Okay, I thought so in May, but this time I really hope I'm right >.>)

Just a quick update: I'm currently working on three things: Making the software much easier to build, creating ebuilds for gentoo users/.dep packages for Debian users and providing a nearly static binary, which should run an most systems. Stay tuned.

Installing CuteCapture on gentoo linux just became much more convenient! Just add the cute-overlay with layman and install games-util/cutedscapture or games-util/cute3dscapture!

I'm currently learning how to use the OpenSuse Build Services, which will enable me to create repositaries containing CuteCapture for many different distributions easily, including OpenSuse, Fedora and Debian. Once I finished that, installing CuteCapture will be nearly as easy as installing any other software. Stay tuned!

Is it possible to get USB audio with C3C?

Not yet. I started working on it, but for the past few months, studying and life in general kept me busy. Can't say when I'll find some time to get audio or binary builds working, although I believe both are not to far from finished.

So today I started work on the audio via USB again. I hope to get it done in the next week or so. Afterwards I hopefully find the time to work on the distribution of binary files again.
[EDIT:] Okay, by tomorrow I'll update the first post to include instructions on how to install C3C (and possibly CDC) on openSuse, Suse Linux Enterprise, Fedora, Gentoo and Arch. If you're lucky Debian and Ubuntu will be ready, too.

I've just updated the opening post with instructions on how to install C3C and CDC on Fedora and openSUSE/Suse Linux. Debian and Arch will follow soonish, Ubuntu needs a bit more work, or so it seems. Also making progress with audio capturing for 3DS. At the moment the sound is delayed by about 2 seconds of buffering, but at least this is a prove of concept - the way I access the audio is correct, but I need quicker playback.
So you could say, after waaaay to long, C3C and CDC are coming along nicely again.