I kind of like the idea...
But a few things
1st, its an ergonomic nightmare. Your neck will probably hurt after a bit. look at the guys sitting position. he will be looking down for long periods of time. Raise it up some and a bit less of an angle will help I think... But you should be able to prototype the tv and the mounting tray very easy with some boxes ect and see. But you are supposed to look straight ahead to see the top 3/4 of the monitor or so. So your head looks a bit down, but not that much.
I've considered ergonomics as the most important factor. I can tell you that my design is thousand times more comfortable than a standard japanese sit-dow cabinets. These force you to keep your back straight, with no place for your legs. The position I take for playing is like the one in the picture, and I can play for hours. The position of the neck is perfect. It's natural. What is not natural is to look up. An example. Sit on a chair in front of your computer in the position you normally take for typing and try this: what is more comfortable, too look for 3 hours to your keyboard or to look for 3 hours at a a the wall in front of your at the level of your head? When you feel tired you end up looking down.
second. you will want to be able to clamp that controller on somehow. Having it loose kinda stinks. Whats great about a cabinet is that the controls are locked down firm and you don't have to worry about it moving.
My CP is heavy (it has a base made or iron). Moreover, it has ant slippery pieces that makes it impossible to move, unless you grab it an lift it. A CP with fixed position is always an inconvenience. An example: you never play centered because each player is on each side.
third. You will want to make sure that the table is at keyboard height. No reason it couldn't be a computer workstation when not in use.. I pretty cool one at that.
I have another computer for working and playing PC games, with a normal table and a mutisync monitor. This is only for MAME and movies (ArcadeVGA + SCART TV). The keyboard is used rarely.
fourth... Consider if you can move the monitor up somehow so you can use it as a TV from across the room. Heck, do this and if you don't have a control panels yet, you can go with two wireless xbox controllers (goto consoles forum to see the one I got... easy hack and fits most arcade buttons and some joysticks). Then you can use it from the couch if you want to lay back.
As I said the monitor has two normal positions (not talking about vertical or horizontal now): inclined and not inclined. The first one is for gaming. The second one is for movies.
fifth.... Is there one? You might consider if you want to go with building a real arcade cabinet instead. I like the functionality here, and probably works for a lot of people better then a true arcade look/feel since it could be used for more then one thing. But if you will only use it for arcade games, you might want it to look like an arcade machine at the same time.
I know it doesn't look authentic, but I prefer something ergonomic, practical, comfortable and modular (even only for gaming) rather than a beautiful cabinet. Also, if I decided to build a real cabinet I would have to build two: one with horizontal monitor and other with vertical monitor. With this design I have everything.