That article implies that switching to a 64-bit operating system would immediately allow Final Cut Pro to access the extra memory. This is not the case. Final Cut Pro would need to be recompiled as a 64-bit application and many of the older 32-bit-only APIs it uses would need to be replaced with 64-bit equivalents. This is not a trivial undertaking.
So until that occurs, the 14 GB of RAM in your computer will be useful only to applications that can address it (e.g. Adobe Premiere CS 5) or for running multiple applications simultaneously.
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