g1smd - 1:13 pm on Apr 30, 2007 (gmt 0)

They will start to list some of the new URLs quite quickly, but getting most of them listed will take at least 6 months. Some might not make it.

Many of the old URLs will remain in the index for many months, maybe even a year. Your redirect will get the visitor to the correct content anyway.

Once any of the old URLs are shown as Supplemental Results you cannot control what Google will show for those. Ignore them and move on. Google will do what it has to do from then on.