4e requires a new way of looking at things.
In earlier editions, fighters were simply better fighters - more hit points, better attack bonuses, more attacks, higher damage, etc. - than other classes. That has largely vanished as a distinguishing feature. They still slightly lead in some of those categories, but the difference is much much smaller.
In 4e, the real distinguishing feature is that fighters have 'weapon magic' and other classes have different sorts of magic as appropriate to the theme of the class. Fighters can, after recharging thier ki (or however you prefer to look at it), do extraordinary magical things with thier weapons. Like the wizard, they can only do most of thier 'weapon spells' every five minutes or so, and only once each in those five minutes, and some of them only once a day. However, they can do amazing things, like automatically overcome a second target's defences no matter how strong if they strike an ally, or 'cut the wind' so that the target is damaged even if they miss, or cause thier sword to reach out and strike everything in 15' square, or move greater than thier normal speed in a flurry of attacks, or knock everyone nearby off thier feet, and so forth (I haven't read the whole book, but that sort of thing).
Wizards are quite unable to perform that sort of 'weapon magic', but are extremely skilled at summoning the elements and blasting thier foes at a distance so it balances out.
Really, combat in 4e is more like 'Mighty Morphin' Power Rangers' or other Japanese/Asian inspired settings. Everyone has secret techniques - ('Unstoppable Bonzai!', 'Water Dragon Tailcut', 'Viper Strike' or whatever) that they've learned through intense training, and they can do these techniques but (most importantly) not repeatedly without first recovering thier chi. So, in a fight, typically you see them try various super techniques but they only use them once before trying something else. It's very cinematic.
