You got it. ATi provides the core and the ODMs do the rest. They'll take the core and implement it into their notebooks however they want to. I'm not sure if the memory on the GPUs are provided by ATi, they might be, I'm unsure of that.
Without a question though, a 9700 mobility in a CL56 will be different from one in say... shoot, i dunno, another laptop with a 9700 mobility.
The CL56 is one of the few that has a removable GPU though. Most ODMs have the core soldered onto the mobo. Compal has the core and memory chips on a daughter card that is removable from the mobo. This would indicate that you can upgrade the graphics card when Compal releases a new daughterboard. However, it's not the case, as I have found and experienced (check my DIY upgrade link in my sig).
Nevertheless, in the future if PCI express for notebooks come out, hopefully we can have a very simple user upgradeable graphics solution. Crossing fingers...