IGN has finally posted their first look on EA Sports Fight Night Round 4, due out for release later this Summer.  On the article they deployed the first in-game video featuring Ali and Tyson:

Some interesting points about the First Look article are:

1) Ability to save replays from your fights and share them online.

2) Haymakers don’t depend on how far back you wind up the stick.  It is now a modifier where a normal hook+right bumper will dish a haymaker.

3) Parry system is out.

4) Boxers can get Stunned by a good punch, in contrast to Round 3 where it was only by a Stun Punches.  When stunned boxers energy won’t go completely down but it won’t recharge until a certain amount of time after you get your legs under you.  Your ring movements and speed will go down while Stunned.

5) Getting up after a Knockdown now has you lining up an “avatar” with the left stick and then picking up your wobbly body with right stick.

6) Every possible stat is saved after your career mode fights.

That and a lot more is here:

http://xbox360.ign.com/articles/961/961736p1.html