Perfect signing, really. If Cech gets injured, we won't be playing Hilario or Blackman, but a man with over 500 Premier League appearances, and over 150 Premier League clean sheets. Him being here isn't going to upset the apple-cart; he'll probably be gone by this time next year, or if Cech decides to leave or for some reason Courtois is farmed off on loan again (can't see this happening, but you never know!), he can stay on for a further year.