RPG: This has been the style of rpg for years. This is the table-top, dungeons and dragons knock-off, crawler, stat based, dice-rolling type game. This is what (in ES) Arena, Daggerfall, and Morrowind where (Morrowind begins the turning point). These games focus on the idea of a game in which the player role-plays, with role-playing being an encompassing term. You pick a character, give them names, backgrounds, classes, attributes, personality, skills, and more and then proceed to play the game as this newly created character. This is imagination at its finest. This is the opportunity to be someone/something else that may even behave completely different than the player themselves might. However, because it is heavily imaginative it requires aid. This aid comes in the form of attributes. These determine how strong, intelligent, wise, etc., that created role is. The player has to be able to say, "The character I created will have a thinner body designed more for speed." The attributes must fit as it describes the character. The player CANNOT suddenly have this role they play start throwing boulders without the strength attribute determining as such. This heavily detailed approach continues on into skills. Every action the role does must be determined by skills. This style of play is where everything about the character is laid out before the player.
Rpg: This is the new trend. This style emphasizes the ROLE in role-playing. What role is that? The player. This is designed to make the player the role. I, as a player, must fill the role of a prophecy, or the heroine, or whatever. It is not about ROLE-PLAYING a character but about playing a ROLE. This is important. This can be found in almost all Bioware games, recent Bethesda games, western developers in general. These games focus on immersion. They are designed to get the player feel like they are that role. It becomes less important to determine everything about a person. The player is already a person. They know how they will respond to quests and problems. They know what skills they have. They know what attributes they have. It becomes less important to have a "Climbing" skill when the player can just do the climbing themselves. There is no reason to dictate that to the player. There is no reason to dictate how intelligent the player's character is when they themselves are already intelligent (not likely but trying to stay positive haha). There is no reason to have a hidden dice roll the chances of a character hitting an opponent when the player is quite capable of aiming and closing distances on the enemy to insure contact. The problem with these type games is that things can easily degenerate into other styles of gaming. Afterall, Halo could be considered an Rpg because the player becomes Master Chief. Yet the difference here is customization. The ability to tailor characters in the game to how players want. Too much customization becomes RPG and less about the player. But too little doesn't allow the player to insert themselves into the game. A proper balance needs to be found in immersion. I personally think that Skyrim, so far, seems to be striking a good balance here. Yes, it seems the days of RPG's are over (people, please quit calling them "true rpg's"). Rpg's are more prevalent. How do we bring players into the game? That is the question rpg developers seem to be asking now. There is experimentation going on. ME2 may have been too much experimentation. There was just enough customization to insert the player into the world, but not enough to define the world.
I personally have developed more into an Rpg player, although I was originally a pure RPG guy. I wanna feel like the world exists, not read the world exists. I am excited for HUD-less. I'm excited for the compass menu system. It keeps the player in the moment. I loved the combat in Oblivion compared to past games, although it still needed work. I'm excited for the combat in DA2. I loved the combat in ME2. Combat seems to be something that has gotten figured out for Rpg's. Now, balancing in other areas need to be figured out.