I got notification on 24th April, failed to download in two attempts. I finally got it installed on the next day, effectively disabling root. Retrying to root with Z4Root without success, the same failure when I tried to root again using Androot after upgrading from 1.6 (donut) to 2.2 (froyo).

After googling around I managed to root my Dell Streak using GingerBreak (http://goo.gl/M2oEo).