So, I was making some experiments on Flashsites on Bing, the result I have is nothing. Bing is obviously not indexing Flash content on its searches.
I tend to think that this is another political issue: Silverlight vs. Flash, but I don´t know if Bing ins indexing Silverlight content. Anyway if we are hand to hand to Google we won´t haver problems.
If you want to register a site freely in Bing, just go here. You can upload your sitemap or apply for an appID, etc. (I have the strange feeling of having seen this anywhere else haha). I saw the banner on hotmail not in any other site.