Dark Souls Interview

Japanese website 4Gamer.net has posted a lengthy interview with From Software's Hidetaka Miyazaki, and while I can't actually read any of it, we're able to decipher much of its contents courtesy of Google Translate and the fine folks at Andriasang.
Dark Souls is expected to have about 60 hours or so play time, said Miyazaki. Demon's Souls, in contrast, expects 30 or 40 hours.

In the area of content, the major point of increase is in enemies. Demon's Souls had around 30 types. Dark Souls has close to 100.

Of course, they're also readying an appropriate quantity of weapons, armor and such. There will be new magic. An example is the ability to turn yourself into objects, which could lead to coming across jars in odd places during multiplayer.

Weapons will have different motions, and some players may choose to keep using weaker weapons because they match their play style rather than switch to more powerful weapons when obtained. The weapons actually see changes in speed and recovery time depending on your character's parameters.

There will also be weapon fortification system in place, an area that Miyzaki felt Demon's Souls failed with. Overseas players in particular said that this area of Demon's Souls was difficult to understand.