The task was:
12 pieces of music. (90 minutes in one setup)
4 of them are pre-recorded (audio)
The others are performed live with a huge load of Midi coming from two controllers:
The marimba lumina and the Lightning II built by Don Buchla.
Sometimes there are 8 different continuous controllers and Midi-notes coming at the same time triggering up to 14 channels of Ableton-samplers and Synthesizers like Omnisphere or Zebra at the same time. (2 players)
The aim was to make a setup with no loading-pauses between the pieces. And no unusable processor-load.
Tipp 1: Organize all the songs in single folders and switch not only the folder on and off with the remote-function (triggered by a simple Midinote-message on a keyboard, but also switch the synthesizers and plugins on and off within the folders.) So the processor-load is minimal. I actually went down to 212samples without any problem. (Using a MacbookPro 2.2Ghz). All together I am using 129 channels in 12 folders.
Tipp 2: Play all the Synthesizers used in the setup before the show once, only a few notes, this avoids a delay ("hickup") which sometimes happens in huge setups. It seems, that then part of the samples are load in the memory of the computer.
On my wishlist:
1. A remote-function for opening the folders. To see what I am doing, I have to open the folders using the mouse, which is sometimes not so easy in a performance where the timing is so important.
2. A way to cover the arrange-view at the top of the screen. When so many tracks are involved one fourth of the screen is taken by kind of useless information, because I am using no arrangments at all in the setup.
First I couldn´t believe this could work in a single computer, but since Live 8 is there I gave it a try. I normally wouldn´t use a fresh update for a world premiere on stage, but with Live I did it, and and everything works perfectly. Great program !
Here are a few pictures of the setup:

setup on stage

keyboard to switch the single parts on and off.

with a single keystroke, many plugins are activated at the same time.

Here are all 12 folders in a closed state

One folder is open with 10 tracks of audio and 2 live played instruments. Scenes are controlled by LightningII.

This is an open folder with 3 audio-tracks and 6 samplers controlled by the marimba lumina.
Now you also can see, that the top quarter of the screen is just empty (because no arrange is involved) and it would be great to get the possibilty to hide it.

And: never underestimate this function, Perfect for live-situations.
I hope this gives you an impression how the folders can be used in large setups.
best wishes
pyro