I've always considered USATF Masters Nationals and the WMA Championships as the 'legitimate' national and world championships. However, there are others. For example, the National Senior Games, the Huntsman World Games, etc...
These other events are all encompassing and include many other sports. But, looking at the results of these competitions in the track events, these events seem very much to me as 'the minor leagues' of masters track competition.
Here are the winning times from '17 World Masters Games in the M55 age group ...
100m - 13.18 (-2.6)
200m - 25.52 (+1.2)
400m - 57.12
Now of course, one or two masters elites would give such or any competition a much greater respectability. For example, in the '09 World Masters Games in Sydney, Bill Collins and a German elite logged times that would win M55 in any WMA World meet in :
100m - 11.76
200m - 23.95
400m - 54.42
There was a discussion on this subject at Daegu about this. A great diversity of opinions was expressed. Two members on team America had opposite opinions: 1) These other events (like WMG) offer more venues and opportunities, and 2) These other events are illegitimate as so-called 'world championships'.
I see both opinions as valid, however I'm inclined to side with the second view that there are only single valid National and World championship entities. The WMA has a relationship with IAAF through a 'masters commission.' The IAAF and the USATF are the recognized entities for world and national athletics championships, and I think it should stay that way.
Whatever, at least there exists world masters rankings, which seems to be the only real measure of yearly masters athletic marks. I don't mind the idea of more opportunities for masters, but it seems that there are already quite a few... state games, senior games, USATF associations, college meets, etc... Bottom line is, I think the USATF National Masters and WMA World championships should be recognized as the sole national and world championships for masters.