There is always a big controversy over naming things in games. The latest DnD Next blog post illustrates this admirably. It talks about how all classes are going to fall into one of four groups - Warrior, Trickster, Mage, Priest. This is fairly iconic division and certainly the grognards from days of old should approve... except of course they largely don't. There are a couple of issues here and it seems the largest one is the choice of Trickster for the group of classes that contains the iconic Thief / Rogue. People really don't like Trickster since in theory classes that focus on scouting, assassination, crafting, or other skills would get lumped in there and that doesn't feel right. People have suggested Rogue instead but I honestly feel like that has just as many issues. The ideal choice from my perspective is something more like Scout or Expert; something that implies that their focus is information and skill instead of magic or fighting. The thing I don't like is that Trickster implies deception and that isn't going to be at all consistent in classes in that group.
Of course there is a bigger problem there and that is that having a class that focuses on skills that are fully bounded by physics is always going to be weak in the late game against the reality bending powers of spellcasters. Those same spellcasters are drastically less problematic in Next than in 2nd and 3rd edition but having a set of classes be focused around being skill experts is going to mean they suck overall. Things don't have to be this way. Dividing the thugging classes by 'good at fighting' and 'good at skills' is a disaster but they could just as easily be divided along the lines of 'tough and solid' and 'quick and dangerous'. Fighters that have tons of HP and lots of ways to defend can be balanced quite reasonably against Rogues that hit hard and have good mobility and escape tactics. Warrior and Rogue work just fine as names for those kits of abilities.
I have my own personal nut against calling the healing group Priest since I would very much like to have options for my healer that don't include worship. This isn't even the crusading atheist in me talking; I have played very religious characters many times and enjoyed it but I would definitely like the option to build a character without such convictions as the healer in the group. The other three categories aren't constrained by a particular belief set and outlook and I would greatly prefer to have a healer group that doesn't have that title. I get that most people don't see it this way though; they could just call them Leaders or Healers or Oracles or something else entirely but most folks seem satisfied with Priest.
I struggled a lot with naming classes in Heroes By Trade. I ended up with Marauder, Champion, Hunter, Tactician, Voidbringer, Channeler, Oracle, Wizard. I feel like between them you can find a home for pretty much any concept and I don't really feel like I need group names even though they can easily be divided by using three separate descriptors - Range/Melee, Martial/Magical, Offence/Defence.