I've noticed WRC cars and F1 cars for example have a semi-automatic transmission with the flappy paddle gear box..  but they also have a clutch pedal and clutch for launches or tight handbrake turns so they don't stall out. 
VIDEO example  
 
   about 5 min in  
  I realize there is obviously a clutch and pressure plate, but is there also a torque converter?! 
  
If this system used JUST a clutch..  how does the transmission shift under load and full throttle for example without "disengaging?" from one gear to the next. 
  
 Im puzzled. 
  
 I found this "dual-clutch" transmission link on how stuff works 
http://auto.howstuffworks.com/dual-clutch-transmission.htm 
  
 If you have a dual clutch system...  is there a primary clutch and pressure plate between the engine and the transmission, as well as the 2nd and 3rd clutches built into the transmission that are hydraulically controlled?