I started work on carrying out the glorious drawing near the end of January - and took way too many pictures:
Made a new shelf for the built in shelving area that is going to become the equipment rack... this should have been really easy, but it turns out the space is trapezoid shaped, so the shelf needed to be 1" more narrow at the back than the front - simple to fix, but irritating to find out! I assumed the shelf I had brought up to "make a copy of" had just been cut like that on accident.
Here is a shot of the (very cluttered) shelves where the equipment will be going:
AVR will be on the top shelf - I will be putting a fan in the wall on the right side to pull hot air away and into the utility room that is on the other side of the wall.
Then I took on the extremely simple job of installing the gang box for the future can lights. The previous owner had an electrical outlet and a switch that was labeled "neon" on the wall - so I decided to put my switches here. Problem is that they didn't space them out very well - here is the wall marked for a 3 gang box:
... not quite...
Here it is marked for a 4 gang box:
... still not quite... but lets try it anyway:
Nice gaps on either side...
Luckily the cover plate I picked up was "oversized" - so it worked out exactly perfectly!
Here is where that is in the room:
Notice the blank plate at an awkward angle up above the switches? They had a phone jack there... and did a great job of lining that hole up

I will be patching that with the drywall I cut out installing the box - and a poster will be going there anyway so it doesn't matter if my patchwork sucks.
Right now the 2 switches on the right are Lutron IR switches that will control the lights over the door and couch, the space with nothing originally ended up housing an X10 switch before I later picked up a 3rd Maestro...
Just to show how the room looked then - here are a few more pictures...
Left side
I already removed one of the "entertainment center" pieces... looks so unbalanced right now!
Right side