I was not actually aware that Kendo uses ippon. I guess it makes sense though. When Ippon is scored, is it like Judo in that any strike with the result you want will score Ippon, or is Ippon harder to score? In Judo for example anytime your opponent goes to his back at speed it's an ippon.
No, ippon is actually fairly hard in kendo, mainly because there are fewer ways to score and more factors surrounding those ways. If you watch a good kendo match, you will see that when a point is scored, the kenshi's shinai strikes a valid target with the mono-uchi (cutting portion of roughly the last sixth of the blade) at the same moment their lead foot steps. The hard step, sometimes called a stomp, is fumikomi. Fumikomi and the actual strike must coincide in order to have a valid point. The cut must also have correct hasuji, meaning that the blade must move in such a way that if it were an edged weapon, it would cut rather than scuff its target. And it has to be a real cut. lifting your point six inches and slapping your opponent's wrist is not a cut, even if you are able to generate a good amount of force.
Somewhat off topic, but what does Zanshin mean?
Zanshin, or remaining mind, refers to one's posture and maintaining one's awareness after making the cut.
Showing zanshin means that if you cut and pass, you go a little ways past your opponent, and turn, demonstrating awareness that the other swordsman could be right there... because he could be, and if your point wasn't score, as soon as you turn around, if your guard is weak or non existent, your opponent may strike.
If you do a retreating strike, you must likewise show zanshin. You don't strike, throw your hands up like you scored a touchdown and dance backward. You strike and then as you retreat, you keep a good guard. In the even that your strike did not score and your opponent pursues you, you will need to.