For me so far
Gerrard and Alonso - good performances and should be relied upon to make things happen from the middle of the park - good cover for both in Sissoko and Hamann - admittedly all four are very different players so will be important to mix & match dependent on opposition. Do think Sissoko has looked full of energy and physical presence which you need in the premiership
Like the look of Whitbread but he needs more time to develop. Not sure i am keen on Potter though - good young talent but not sure he will make the grade for more than a few sub appearances. Same i think is true now for ALT - a good game against BL linking well with Cisse but was largely non-existent in the bulk of the matches he has played pre season.
Zenden - good crosser, but not sure he has the pace to trouble a decent right back. Good work rate though and seems like he will fight for the team. Also popped up in the box on quite a few occassions so may well chip in with the odd goa.
Reina - hard to say given the opposition so far but does look more solid and self confident compared to Dudek. Very assured coming for crosses or decisive on punching vs catching.
Not convinced about Cisse though - he is my main worry if we are to rely upon him as the first choice goal getter. No doubting his pace and great return to fitness but even before he got injured my concern was that he is not a 'finisher' - seems more hit hard and hope most of the time - not in the Henry or Owen league re deftness/craft of finish especially 1-on-1 with a keeper.
Crouch - no complaints but need to see more. Same for Morientes although lack of pace seems to be a common theme in pre-season so far with him - perhaps better played in European games in a 4-5-1 with more goals coming from midfield/flanks