as above I have just bought a 15" macbook pro retina and also upgraded the processor through Apple at time of purchase so that this one won't struggle with PS and LR on my wacom cintiq 24HD touch. Can someone please tell me how I can transfer my LR catalogue to the new computer.
By default catalog stays in the pictures folder.
Copy the Lightroom folder from your pictures folder of old mac to new mac.
Inside this Lightroom folder there should be a file or files ending with .lrcat format , this is the catalog file.
Open the last used catalog file.