Here is how I stand on the situation:
I remember when Alonso left, I was gutted, but I thought that he could be replaced. I seen some people saying "Liverpool will be crap without him" and we were (this isn't the only reason why!).
Whilst Aquilani didn't make an impact last season I still think he will only get better, and may be one of our most important players this season. He barely got a game last season due to injury, and when he played I thought he created a few good chances and he looked like he could be a good attacking player.
I think another central midfielder would go a long way, even if Masch stays (which I don't think he will). Defour looks promising and as someone said yesterday on here, he is like the Gerrard of his team. I know he plays for a far smaller and easier league but, if has even half the influence Gerrard has, then I think he will do very well in a Liverpool shirt.
If Masch goes we will definitely need a good replacement. Someone like Banega looks promising, but if Hodgeson is looking for English players then Cattermole is a very good option. My only concern would be the amount of injuries he seemed to pick up last season.
I think people tend to use the Alonso excuse too often. I think one other area which really let us down last season was the defence, maybe even more so than anything else. I don't necessarily think it was down to certain individiuals but more down to tactics.