The only hub I knew before I discovered hubpages was the resurrection hub in Battlestar Galactica :D I still didn't know what hub means until I checked a dictionary a minute ago.
Anyway I sensed it was a use specific to this site and stuck to article in hubpages and bookmarking sites. I agree that it would be confusing for those coming through search engines.
But perhaps one day this site will become something really big and the word hub will be a brand word, something like wiki. Then we will want to use the word "hub". That day is yet to come yet though.