May I ask you why?
Picture the PH1 Fighter, listing only the Marking ability (but not Combat Superitority), Reaping Strike, Cleave and one Encounter power. What myriad options does he have that what we've seen from the knight so far doesn't?
Instead of having two different at-will powers (which are just alterations of a basic attack), the knight has two class features that alter his basic attacks. Instead of having a mark that requires him to attack a creature, he marks every adjacent enemy.
At the end of the day, the Guardian Fighter and the Knight Fighter are doing the same things in slightly different ways.
I think that's a fair point. We really may not be seeing the most important features of the class, and I'm happy to say I'm wrong if there was something more interesting that isn't being illustrated here. I am a pretty big 4X fan and I want the line to succeed.
With that said, I'm bored with this class because there isn't much to it. Is it a bad preview? Well, time will tell, but we have at wills that do a small amount of extra damage or cleave. The encounter is rolling an extra die of damage once per encounter? Ugh! Now I have already seen that there's a huge amount of extra damage that can be added on to a basic attack, so I have no doubt we'll see a very strikerish form of fighter is easily possible and that could be a useful addition to a group.
What I'm not seeing is a strong defender aspect to the class or any real amount of control. I play a fighter at the moment (and this is the first edition I've done so since back with first edition!) and the thing that got me interested in the class was in a discussion of a martial controller. Someone (and I forget who it was) said you don't need a martial controller, because the fighter is it already.
Once I read that, I was intrigued and decided I'd write up a character who was designed to control the battle and manage it. One of the other players in my group plays a warlord, and together we pretty much handle the flow of combat in that group. That's a very complex character to play that's a lot of fun for me. Now I certainly wouldn't expect Essentials to give me that level of control, I'd expect to see something more than their Defender Aura.
What this preview is showing me is a very simple character who can do a fair bit of damage, but not much else. I think there is a strong incentive to have that kind of character available, since there are players who want simplicity and to do some damage and have that 10 second turn. Heck, I've already seen that with the new magic missile: at one of the Encounters I was at, a player just pointed at a monster and announced it took 5 points of damage as his turn for the entire battle!
Maybe the new Essential's fighter can do more controllery and defendery sorts of things, but we're not seeing it here.
So that's my thought... I'm not calling this a bad class, it's just boring from what we've seen. And if there are all sorts of interesting things we haven't seen, well, I'd say this isn't the best preview.