So, I've been crazy about getting Qt3D compiled for Maemo 5. I went as far as trying to compile the full Qt source on the N900, because Scratchbox is so hopeless.
But, a couple of minutes ago, I found the official Qt FTP, and how do you know... The libraries were right there!
These libraries are interesting for many reasons: They let you write next-generation OpenGL apps, easier than ever, and also give you access to lots of new goodies, so you won't have to write it all by yourself.
This is the location:
ftp://ftp.qt.nokia.com/qt3d/maemo5/current
I hope that you'll find this as useful as I did.

The actual goal behind Qt3D is to make a unified way of writing OpenGL apps. Right now, the normal way is writing for a specific platform: OpenGL or GL ES. Qt3D is what should have been: One way for all platforms. And as far as I can see, this works well.

Can't wait for your first app with 3D UI then.

cuteTube-QML with a cube UI, anyone?

Yeah, something like that.
I'm going for a 3D engine, now that the conditions are correct. (Secret plans...)

I wonder if these libraries could be put into extras-devel?
It is a tech preview, but they do work..?

I'll be looking at optifying these so that they're easier to deal with.

It would be awesome to see the idtech3 (Quake 3 engine) ported to Qt3D so that all devices can have a decent 3D-game as long as they support Qt.

And you know, the other hundred of (community built) games that are built on id3... FPS Angry Birds anyone?

I've done some testing, and found that the cap on QtQuick 3D on the N900 lies around 50kpoly. Beyond that, your GPU will stop rendering any more data, so it becomes an incomplete render.
It goes out of memory, in other words. I wish the N900 had more than this. I tried loading a 256k poly model, but it froze. (I wouldn't recommend doing the same as I did.)
I've yet to see if it can handle it when you use multiple meshes to distribute the amount of polys across them. It is possible that it would work, and there is a possibility it won't.