The thing is that we see keepers like Van der Sar and Buffon who were still top keepers in their late 30s and generally believe that the general trend amongst keepers is that they retain their ability that late into their careers when the truth is very few actually do. Once a keeper hits the age of 33/34 the decline starts to show a little and with Cech it's obvious he isn't the keeper he was 10 years ago. I think VdS late career success skewed a lot of people's perceptions regarding the longevity of goalkeepers.
I foresaw this because even in Cech's final season as Chelsea number one you could see he had slowed down and even with the national team some of the goals he was conceding were either very soft or downright comical.
I'd advocate bringing back Woj in the summer in the hope that his impressive form in the Italian capital can be translated back over here.
Either that or sign a top keeper.