I had read a while back that AT&T was deploying a software update that now includes the split- or dual-screen display. (It came on European machines, but not on USA carrier machines but is now available--at least on ATTicon.)

If you are on AT&T, you can check to see if it is available in your area by going to Settings > About Device. Then click Software Update.

Read my experience here:
Samsung Note II 4 You: Update From ATT-Split Screen