Well, the drive arrived this afternoon. I had already backed things up over to the Storage drive on my server for safe keeping.
As a whole the upgrade could not be easier, simply follow the instructions given by Apple in the DIY pdf and you can't go wrong. Note, you will need a very small Jeweler type screwdriver for inside the battery bay.
One thing the DIY guide does miss out, although common sense while carrying out the upgrade should make you aware of this. There is a heatshield (part with tab attached) which is fixed to the drive, there are 4 t10 torx bits to remove, then its a simple case of transfering the heatshield over to your new drive. If you do not transfer this heat shield over, chances of you removing the drive in the future will be slim, as you won't have a tab to pull the drive out with. 🙂
When you boot the Mac up for the first time, with your installation media present. Remember to visit the Drive Utility first and create a Mac formatted partition. Otherwise you won't get very far in the install 😛
The Macbook is now checking my installation media and hopefully I will be able to install OS X without a problem. I will update this post after it is installed and I have transfered my files back over.
I have upgraded the Macbook Rev.1 from a standard issue Seagate 60Gb 5400rpm to a Western Digital Scorpio 120Gb 5400rpm
edit; One observation is that this drive seems to run 4°C hotter.