Is Eye Of North the newest Guild Wars, and do it got all the new classes that was in factions?

Eye of the North isn't a seperate campaign like Factions and Nightfall. Eye of the North is one that you can access from a campaign. In game, at certain outposts, there will be a quest that you can take. This new quest will direct you to the EotN story line. The expansion takes you to a land north of Tyria (prophecies campaign) to add to the game. The EotN Campaign is an expansion meant specifically for the purpose of adding to the Prophecies campaign. For maximum fun, play through the Prophecies campaign to help you understand the plot of EotN in your latter travels.