I would assume it is manual and begin the process of reconsideration (immediately due to them taking a while - some two to three months). The reason I say that is that there is nothing in Site:url. I cannot think of any other reason that there would be zero indexed pages showing. 
Have you looked on Bing for cached pages (out of curiosity more than anything)?

Ryan,

I am assuming you have gone into Bing Webmaster Tools, but in case you have not, here is info re determining if a penalty exists:

Bing says:To determine if a penalty has completely blocked your site from the Bing index, log in to Bing Webmaster Tools, and review the messages to the webmaster on the Home tab. If no messages about penalties are found, select the registered site in question from the SITES list, and then review the Index Summary chart on the Dashboard tab. If the number of pages indexed has dropped down to zero, then your site has a severe index penalty levied against it. Note that Bing Webmaster Tools does not currently display the status of lesser index penalties. (NOTE: Italics above are mine)

On the chance you have been penalized, here is the link to reconsideration; Bing Support Re Reconsideration

I have not suffered a penalty on Bing and called a few friends and none have experience. Sorry I could not be more help.