Me and John have both probably tried to explain the way The Secret World's classless progression works using nothing more than the power of words but it's much easier to use visual aids as well, so I'll hand you over to Funcom's Martin Bruusgard and Joel Bylos who explain what kind of abilities are available and how they can be combined to make effective characters. I've had some experience with switching functions on the fly during my time with the game, mainly at the points when I realised I was completely inept in the role I'd been given so I went for something simpler instead. I like to think my eventual role was attractive spectator.
Does it all make sense now? I enjoy Martin's interaction with the graphics almost as much as I enjoy Joel acting as if he doesn't know anything is going to be superimposed around him.
One of the features that I haven't been able to play with in person is the clothing and character design. I've always just been 'angry man in dapper suit' or 'lady in shorts', depending on how the mood takes me. I'm glad I'll be able to dress to my mood without it affecting my ability to play in a certain style, although when the style is 'attractive spectator' perhaps the clothing will be the most important part of the puzzle that is my Illumaniti gentlething.