Despite Juventus obvious holes in their starting lineup they still have the quality to overcome the likes of roma, genoa, sampdoria, palermo etc.
The reason those teams look "good" for the new season (barring roma) is that juventus (milan too, to an extent) was so damn piss poor (for reasons fred stated) that it deceived people into thinking that those other teams are quality.
Case in point: Werder Bremen - Sampdoria