As a senior member of the TES, modding community, I can attest to ability of good mods to lengthen a game's life and breath new life into it. BS has unlimited modding potential. If you don't believe me see here: Oblivion Mods or here: Morrowind Mods. 2K is blowing a huge business opportunity here as well as a chance to regain some measure of street cred.
Since Ken Levine has said in the past that there would be an editor (amongst other broken promises), I basically perceive him as being untrustworthy. Ken prove me wrong.
Just my two cents.