yes he already did
actaully in one of the episodes he reveals it to his parents, but as for the world, that's in ben 10 EVOLUTIONS
That is an opinion question and can not be answered.
Yes, in fall 2009
It depends on which one you are talking about? In Ben 10 Secret of the Omnitrix Ben is 10, in Ben 10 Race Against Time Ben is 10, and in the new Ben 10 Alien Force movie that will be coming out in Fall 2009 Ben is 15.
Diamond head, Ghost freak, Four arms, Grey matter, Heat blast, Wild mutt, Xlr8, upgrade, Ripjaws, stinkfly, cannonbolt, Eyeguy, Ben victor, Ben mummy, Ben wolf, wild vine, upchuck, ditto, eon, way big, and ghost freak (true form)
2012 or 2013
no
no
He has not Appered yet , but you can go to cartoonnetwork.com ,click on Ben 10 Ultimate Alien , and listen to his voice.
ben 10 rocks.he is stronger than naruto and goku.William is the coolest and strongest guy ever.
actaully in one of the episodes he reveals it to his parents, but as for the world, that's in ben 10 EVOLUTIONS
I am trying to find that out 2, the only one i know of is Ben 10 Season 2 episode 7 Tough Luck
when he went into space and threw Vilgax into space
Maybe not because they are trying to make the show better
They appear in the ultimate alien theme song! (2 the sides of ult. cannonbolt)
his alien force aliens and nanomechNo, Alien X doesn't appear in Alien Swarm.
That is an opinion question and can not be answered.