This is pretty much old news, which I for a great deal of time have neglected to write about, solely because of the fact that I forgot to - bummer.
The class system is simply put the most simple, realistic and brilliant system I have ever seen in all my years of gaming. In most western RPG's, you get to choose a class, which most usually specializes in either Melee combat, magic or stealth - A concept not lost on the previous Elder Scrolls titles. Since the poll on this site clearly states that the majority of gamers began their adventures in Tamriel with Oblivion, let's use that as an example.
In Oblivion we could pick one out of several classes, after our tiring endeavours under the Imperial City prison, or we could create one ourselves - again choosing a specialization of either combat, magic or stealth. Then we picked out 7 major skills, causing us to level up when we used them.
The Elder Scrolls has also been about immersion and being who you'd like to be, which is why the developers takes it to the next level this year and completely remove all classes from the game, which saves us the trouble of having to greatly regret our choice at the beginning of the game, as we suddenly figure out that we want to be something else.
This also means that there'll be no major or minor skills, holding you back - suddenly have a change of heart and want to change your days of dirty close-combat to something that seems more dignified and sophisticated like, say, a pyromaniac magic-user? No problem!