There is a prenup, so it looks like assets were not a big issue. The bigger issue, of course, was child custody. Sophie wanted the kids to live with her in the UK, and Joe wanted them to stay with him in the U.S.
According to settlement docs, obtained by TMZ, "an amicable resolution on all issues between them is forthcoming." Translation -- they're super close to signing a settlement.
In the meantime, they have agreed to a temporary child custody agreement. Under the terms, the 2 kids -- ages 1 and 3 -- will be with Sophie from October 9 through October 21. During that time, she's allowed to travel with them to the UK.