I'm probably speaking from a very small minority, but if DW is going to offer to host media, limiting the filetypes that can be uploaded is going to be... annoying. I for one have had the thought of "OK, this I want to share with people" from stuff I have built in Minecraft, but that would have to be shared as an archive (zip, or tgz, or 7z, etc) which does not fall into the available list. Also, stuff from Lego Digital Designer (Yes, I'm a geek, you know this denise) is sharable, and creative, and not on the list. I can completely understand not wanting to write code to cover metatdata for every possible filetype, but not having it available to post as would be.. kinda crankymaking.