Right some more details for you's:
I managed to install the software using the 'Pacifist' app to bypass the official Apple installer software and therefore the System Requirement check and the software (so far) works without issue. I'm not even hacking the software itself, The software itself is completely untouched. This is not like what some people do with FCP6 and hack the program itself to make it work with machines that don't have Quartz Extreme or what have you. This version of FCS3 was clearly designed to work on PowerPC machines, at least to some extent. From what i'm observing, it looks as though the Intel only decision was made right at the last minute.
When i loaded FCP7 on an older 1.9ghz iMac G5 machine to test it, it said FCP required a 2ghz G5 processor, and this box was new, it didn't look like the box you got on FCP6 when you were missing a required hardware feature. So FCP7 clearly is designed to work on a G5 processor. FCP6 needed a 1.25ghz G4 Processor. So it's not as if it's an old requirement stamp that has been left in the programming.
As you'll see from these pictures below, new features that i've tried seem to work too. Admittedly i haven't tried every single feature, but so far i've had nothing but success. Even Motion 4 which is very processor and GPU heavy actually works faster than Motion 3 did. I checked all the components and apps that installed with the software and they are all 'Universal', with the exception of AVC-Intra support which is an 'Intel' only build.
Some screenshots here:
http://www.bpirozzolo.com/powerpcmotion.jpg - The new features of Motion like Reflections, shadows, framing camera support and depth of field all work perfectly, and on our G5 PowerMacs with the 256mb Nvidia GPUs work smoothly and efficiently.
http://www.bpirozzolo.com/powerpcfcp.jpg - FCP7 as you can see loads fine, new features like the new speed tools work without problems. I outputted the FCP timeline display via a Formac box to a studio monitor, all with no issues.
http://www.bpirozzolo.com/powerPCSTP.jpg - New features in Soundtrack Pro work very well too.
So what doesn't work? I'm not stupid as to think that i KNOW that everything is going to work, but from the testing i did today everything seems to work very well.
If you're like me and have 30 Power Mac G5 DP2.5ghz machines at work which would be ridiculously expensive to replace AND some Intels which you're going to buy FCS3 for anyway, you might as well at least TRY and get it to work on the machines. If it produces problems at a later date then fine, replace them. Having a dual economy of FCP6 and FCP7 would be useless for us, so if there's a possibility of FCP7 working on PowerPC, then i'm taking it! Better that than a £50k+ hardware spend thank you!