The 12" mix is available now, streaming, for U2.com subscribers.
Without the "regular" mix to compare it to, it's hard to know how this will be different from that. But it sounds great -- extremely catchy. Immediately reminded me of Bryan Ferry/Roxy Music! Lyrics are a little mushy/obscured in the remix version but from what I've heard this makes a great addition to the album.
When I re-do my album rankings I am pretty sure SOI will rise to #3 or #4. Can't wait to hear the other tracks coming out soon.