Thanks kurt99909! - Jinster, yes, some of the free-hand cuts are a bit wavey. Hopefully no one will see them on the final product!!
It's been a while, but I can assure you, progress is still moving forward with the Ultimate Computer Desk!
I finally got around to assembling the left-hand cabinet - here it is, all glued and clamped together. It's a really solid unit - the dado cuts lined up really well, and the structure is rock solid.


Here I am doing a mock-up of the right-hand cabinet. This one was a little trickier to put together. There is a pretty specific order of assembly, otherwise, you're left with a piece that just doesn't want to fit properly.

Some outlines for the motherboard I/O and power supply

I remember mentioning that I free-handed the holes with the router for the left-hand cabinet. I decided to play a safer route for the right-hand cabinet.
I took a piece of wood, lined it up with my straight edge, and ran my router on top of the wood with a straight bit - this game me a perfect "stencil". What I can do then, is take the stencil, line up the edge with a line that I've drawn on the target piece, place a straight edge behind the stencil, clamp down the straight edge, remove the stencil, and run my router across the straight edge for a straight, accurate line.
Wow, that was a mouthful.


And the end product:


And then I made a pretty huge mistake...
Here is the suspect:

Bam. Can you guess why this was a bad idea?