Multiple-ball pong game AI help

I had this really cool idea of making a pong game with multiple balls (depending on the difficulty level), but then I thought, how the hell am I going to figure out how to code an AI which is smart enough to go after many different balls? So yeah… I’m looking for concepts on how I could do this well enough for it to be functional… but for now I’ll just complete my game so far to have it work for 1 ball at least for now. I plan on using three different modes defined with a global variable (easy, medium, hard), increasing amount of balls with difficulty and amount of time the balls stay in play. Also I’ll try and make some powerups (longer paddle, shorter paddle, faster ball speed, slower ball speed, etc.) which the player can go for.

Thanks in advance for the AI help.

Edit: I originally got the idea from a flash game I randomly found in a game index: http://utopia.duth.gr/~ap7852/FLASH%20GAMES/4%20Ball%20Pong.swf
I’m kind-of trying to re-create that type of AI, but necessarily as quick as that one…