OGaming has an interview with the Engineering Director of Dungeons & Dragons Online, Justin Quimby.Below is a snip:

OGaming: Obvious, but important question: Given that most MMOs are rooted in fantasy origins, why has it taken this long for a title based on Dungeons & Dragons � a game that‘s essentially the great grandfather of them all � to come out?.

Justin Quimby: One of the big things to consider is that we wanted to do it right. Dungeons & Dragons is something that a lot of the folks here in the office have been playing for a long, long time. We wanted to be sure that we could do it properly, and bring that passion into the online space. Another thing that‘s important to note about Turbine is that we worked on Asheron‘s Call and Asheron‘s Call 2, and thereby wound up creating some great technology that allowed us to make D&D Online a reality.