Somewhat agree with HP on the Dominance factor.But is'nt it the same dominance that caused a fall in popularity? that is what ur point no.2 propounds.so is that detrimental or advantageous?
I believe it differs from sport to sport.In the examples that you mentioned,in Formula 1,dominance was affecting the popularity but only after some time elapsed and it became monotonous.But I don't suppose Woods popularity took away the sheen of Golf.
and it is this same dominance that spurs on the second rung players to perform better thus livening up the proceedings.
Even in team sports,dominance sometimes can be attributed to individuals
eg. Sports like basketball.most of the Bulls' dominance was attributed to Jordan and upon his retirement,they were out of reckoning and now are a middle-rung team.
In the case of pole vault,is Yelena Isinbayeva's dominance detrimental? I'd say no. Even if the dominance continues it may not get boring coz there will be enough contenders to grasp our interest.
All in all I am repeating the same thing what HP saar said,that it is these dominant forces that raise the level of the game and its only when there is a dominant force, we can enjoy the best of the sport.Thatz because the level of challenge will be proportional to the level of dominance.
So as long as dominance does'nt lead to monotony,it is good.
Another thing is that,it is a common practice (atleast IMO) is to support the Underdog(s).We won't support a guy at the top but instead will root for the second-best and hope that he/she will beat the player in front of him/her one day or the other.But this again differs from sport to sport.
We've seen that the support is equally divided between Australia & England.
Some root for England beacuse they want Australia's dominance to end and see the rising of a new world order (

@jasz)
Whereas Some (Incl Me-the underdog factor notwithstanding-) root for Australia beacuse we'd like them to continue playing at the top and setting new benchmarks for others to follow.
But as Sport is agreat leveller,everyone gets his/her due someday or the other.So we should cast aside our Favouritisms once in a while and savour the best of it.