When you upgrade to the new version, does it include everything like manuals etc, or is it just upgrade disks?

It includes everything.

It should be exactly the same as the full version but it requires and existing valid serial number. Or at least that has been the case with past versions...

Thanks guys. I always wondered but never asked.

For some reason though when I bought the upgrade from FCP2 -FCP3 I remember only getting "some" documentation covering the differences between the two. I may be remembering wrong though. It would be nice if it came with all the manuals but I only have the FCP2 books and now the FCP4 books (because I bought another "FULL" version). It would be a good question to bring up at the Apple Store to find out for certain.