as a developer who works for a company that owns tons of forums, i wish you luck! not going to lie, but you have a serious uphill battle ahead of you since this forum already has a strong user base and tons of content.

your skin looks a bit depressing. I would suggest some color to brighten the mood a bit.
also, keep your number of subforums to a minimum at the start. the more you have, the more segmented your community will become. users will get bored.

edit: if it does take off, i would seriously looking into picking up the .com