Thanks Cold who has let me know that the plumbers have been called in again at Microsoft after build 1086 leaked to the IRC somehow where it's making the rounds. The file is 128,140 KB so not alot different from earlier builds and I'm told that this version features an evaluation message on the desktop (something not present on build 1081).
Beta Testers have not received this build and all indications point to the fact that this is an internal release only. We'll keep you posted if we get anymore information.
Note: This build will not work correctly with Style XP, which is currently updated to 1.0g that will support any beta SP1 up to 1081 [ link to download info ]