(from the "Part 2" thread)
Of course Morrowind has voice acting, but to the degree of Oblivion and Skyrim? Morrowind has maybe a few hundred lines of spoken dialog...that's it! I think it's very clear that the dialog is more text-based than voice. Oblivion and Skyrim required much more time to make because there is so much spoken dialog and that's what eats at the budget and development time, thus removing the possibilities of alternate courses to take for the player.
I have a different memory of Morrowind than you do as it seemed to have more than just a few hundred spoken lines, but anyhow:
The development time of Oblivion was no more than Morrowind and a little more than Skyrim. Todd Howard even stated in a video interview last June that Skyrim's development wasn't started until after Fallout 3's release, that makes it three years, and I bet the game was mostly completed 6 months ago. IT took a short time because the engine is nearly the same. Oblivion was started shortly after Morrowind and took less than four years, but the engine was new still. Keep in mind, that Morrowind partly used the Gamebryo engine that Oblivion and the latest two Fallouts used. Skyrim's game engine is nothing more than an updated version of the Gamebryo engine, though Beth made claims to making a totally new engine. Making the engine to a game from scratch is the hardest part of game development and can take up to three years of the development time outside of creating the story, characters and writing.
As an example, Dragon Age Origins used a completely new engine, and that game took over 5 years to develop (they started development on it shortly after the release of KoTOR in 2003). Dragon Age 2 took less than 2 years (mainly due to re-using maps) because it used a revamped engine used in DA:O, so they didn't need to do anything in that area, except write the dialogue and create the characters and maps. Keep in mind, that DA2 used all voice acting, and it took less than 2 years to make.