Some good responses and good points raised there.
A few things I'll pick up on...
I honestly don't think Agger/Skrtel are the future for centre half. Both good players but not top players. Skrtel will not be a top player because he doesn't have the ability. Agger will not be a top player because he'll never be fit long enough to keep developing his game, although if he wasn't as injury prone I'd say he had potential to be a top player. Interestingly BOTH are currently injured, which gives me great concern, especially given our 4th, 5th and 6th choice options for CB have gone (Hyypia, Arbeloa and I supposed Hobbs, respectively). There is literally nobody else apart from youngsters.
I agree with Scottbot's point that Carra needs someone better in the air beside him, and just maybe he'd start to look a better player again. We have never really replaced Hyypia in that respect.
Personally I don't think we HAVE to win the league this season, but given Carra and Gerrards' advancing age it may be the best chance we have for a while. I do think we at least have to challenge for it.
The last thing I'll mention is the point our mystery poster made as relayed by Igor - if we don't win it and we need some rebuilding next summer, do we let Benitez do it? Very interesting one. A lot will depend on how well we do this season. If there are signs of us going backwards rather than forwards then there's a real possibility that the pressure will be back on the manager. Should be an interesting season.