After effects , is a great thing for creating 3D Animation or as the name suggests , adding the Effects after everything.
Sony Vegas , something which is more available to people , is something which everyone uses ..
Although it is Used for Basic Video Editing , maybe something like Home Videos , but Sony Creative Software has Pretty well justified Vegas to be used for more cool things.
Back to After Effects , It has got those awesome plugins which sometimes are used for making background loops which could be used for Sony Vegas Intros
After Effects also has A User friendly highly graphical Interface , where you can do operations directly on the screen
I Recommend the use Of Both and If you are into Video even a Nibble , It is the best to have both of these great Video Programs .
Een though , I am still confused about The Next Intro Template : After Effects Project or Sony Vegas Project?