Well allow me to tell my experience with this method. I haven't actually opened the case and put the AC next to the PC. This would be a stupid move on anyones part. But, I have had extremely good results from the way it's set up now.
In my apartment I have a new "Danby - 9900BTU - AC/Dehumidifier/Fan" This unit is actually positioned right across from my PC. The cold air actually blows directly over my PC from across the room about 10'+. Normally I have the AC set to between 72 & 74 F.
My PC case as said in my sig, "ThermalTake Shark" This case has two honeycomb side panel openings that are open to the inside of the case. Ambient air inside the room can pass into the inside of the PC. (Not good for dust, but i keep it very clean) I also have (1) 120mm intake fan & (1) 120mm exhaust fan. anyway... I've noticed that when I have the AC running at low temps... My case temp is normally very close to the setting of the AC. My CPU / GPU / HDD temps are all nice and low at IDLE as well.
BUT. When I turn off the AC for a few days... All of those temps are noticably higher, I would say by at least 5 to 10 degrees. Most notibly the CASE TEMP. Lower case temps for me = slightly lower component temps. The air flow inside my case is very, very good. So i've realized that pretty much what ever the ROOM temp is, is basically what the CASE TEMP is. So in closing with my AC keeping my room cold, it keeps my CASE cold, in turn slightly helping in component cooling...