After watching the game last night I noted a few things as well - a lot of which have been mentioned already.
Glen Johnson seemed to overcommit which is very unlike him - he normally waits for the attacker to accelerate away before using his own pace to win the ball. Yesterday he seemed to lunge into tackles and miss the ball completely - might be a bit keen to prove that he's fit.
Carragher - Still the intelligent defender we can always rely on, but his lack of pace is becoming more and more evident. Without a quicker defender to partner with it'll be difficult to deal with strikers who aren't dead slow.
Agger - Played pretty well imo, probably our first choice centre back when he's fit. Only concern might be if he partners with carragher and he starts bombing forward and unleashing shots - if the shot isn't great and we get caught on the counter, carra is going to have to concede a yellow card at least when a through ball is played to a quick striker. Hopefully he'll choose his opportunities to go forward more wisely - but he does seem sharp and proved that by getting two goals from the corners.
Adam - Great to watch in midfield when passing, creating and shooting but seems quite poor when tackling so far. We're lucky to have so many centre midfielders to work with and he's definitely one we're going to use quite a bit.
Henderson - A player who I think is going to be a valuable member of our squad this season - probably can play in any position in midfield and do well. Smart player who works hard and makes intelligent runs. One of the best at playing the ball on his first touch (if you watched him at sunderland last season) and I think for such a young player his vision is pretty good.
Downing - Finally, we have an out and out winger. He's good with both feet and can cross and score with both feet too. Out wide we rarely see our players trying to beat opponents and get a cross in or take on the players to get a shot in - you need good acceleration to do that and players like kuyt don't really have that. This guy, however, does. His touch is good and I feel Carroll will definitely benefit from this new signing.
Aquilani - Brilliant. Pure class. I feel if he's given a full season to show his worth, he definitely will impress. Made an instant impact and I personally feel his vision is incredible. He can shoot extremely well and can slice through defences with just one killer pass. Please keep him.
Carroll - I'm still seriously undecided - I don't want to judge before he gets back into his full stride but at times his touch is so extremely poor and sometimes it's pretty good. Whatever it is, he's definitely a handful for defenders in the air. Hopefully our players will play to his feet as well because he really has a stinger of a left foot.
As a whole I was very impressed with last night's performance - though I feel the goals we gave away were quite soft bar the last one which was just an amazing strike

Can't wait for the game against sunderland - (i reckon many of the players who will start vs sunderland won't feature for more than 30 minutes against valencia)
Excited for the new season

Excellent overview. I wish i had time to watch the game.