Winning a league is all about creating right environment a combination of good coaching, quality players, group-bonding, support from the fans, and of course injuries. Inter, in the past, has quality players and support from the fans, but they always lacked that extra team effort, and good coaching that could harness individual brilliance. They also have a burden of not winning league, for god knows how many years, and dealing with such kind of pressure is always a disadvantage.
This yers Inter, IMO, is an unknown quantity. On the one hand, they have really talented players who have something to prove: Veron is coming off a bad year, Davids had all sort of problems last year, Adriano having won anything yet, Vieri had a annus horribles last year, Martin ditto Adriano, Recoba (well as usual), and Cannavaro coming off a year to forget.
Players who have something to prove is dangerous because they have incentive to work on their game, and show what they are capable of.
They also have mixture of youth and experience, which is always a good combination IMO. More importantly,despite Manicini saga and big name arrivals, Inter believe has been quite sensible on the transfer market. They signed Veron on loan, Davids on free, Burdisso for petty some for a player of his quality, and Cambiasso also on free. They proved to be prudent this year. And I doubt they are finished just yet: I can see them trying to deal Vieri and Cannavaro to get players who might fit into their team. I think they can do with one more winger, linking forward and young backup GK.
The key of course is how Mancini can get this group of talented players into playing good football. And that is unknown factor X in my view. I have no idea how Manicini's attacking philosophy would fit into current Inter team. And Mancio seems to be one of those managers who gets along well with his players rather than being a displinitarian. Whether that would be good for Inter nor not, I have no idea.
However, one thing is sure, they would be a fun team to watch both on and off the field, and they would be more of a threat than they were last year.
P.S. How many players prior to Davids have played for all big 3 in Serie A?
Only one I can think of is Robby Baggio.