I don't see any team dominating the league for a while because the level of teams in the top 6 is closer than ever before.
The only way I see an a team dominating the premier league over a 3-5 year basis is if man city get rid of that idiot of a manager, get a top class manager in who will buy the right players and instill a mentality for city.
Other than that, the level is too close for a team domination in the epl at the moment.
Even if man u got cantona type figure to be the focal point of the team for the younger players, the teams around man u are a lot stronger than the teams around man u in the early to mid 90's where you had Aston Villa, Norwich, Blackburn and Newcastle challenging with them. Chelsea, Arsenal, Spurs, City and ourselves are stronger outfits than those teams and have either better or the same resources as man u than those teams, so whilst Man u will always challenge for the title - I can't see domination for them or any other team.
Actually Wilshere would be their ideal signing I suspect. As mentioned they need a central midfielder.