I like early Metallica and love Reed's album Berlin, but I'm still totally bemused by this. I don't know what to think - kinda came out of nowhere. However, at a push I'm suspecting it'll be an interesting curio but epic fail.
Until we hear it (a leak, a sample, whatever), I will remain hesitant. It may not be a bad thing; but considering Metallica's track record for the past 15 or so years, yeah.