Is the plan for the experience curve traditional PnP design (double the xp from level to level), an exponential curve or something else?

At this point we’re still experimenting with different curves and functions and the like. What’s nice about our tools is that it’s very easy to tweak values like experience curves. Most likely we’ll be similar to the traditional curves you’ve seen since the early days of D&D and then into RPGs and MUDs, but with a few twists and adjustments to make it MMOG-friendly.