Film Score Monthly doesn't have access to DC as it's a Universal property and I think they're limited to MGM. Besides, it's too recent to fit in their Silver or Golden Age Classics series.
The label that will be releasing it is going through some company changes and has been working on the DC album for well over a year. For 30 days it will be available exclusively through their online vendor, after which other online vendors will also get to offer it in their catalog (like Intrada), but don't look for it in stores.
I'll provide all the details as soon as I get word of it's official release. Very soon!