Beginning to feel sorry for you spuds with no reply! As far as I can see there is only Windows Defender in Beta 2 not 3. I have "signed up" with MS for various newsletters which have proved to be very useful. PCA seems to be a day or two ahead of the game but the differing MS newsletters are useful reminders.
If it helps (probably not) I have had a recent WGA "upgrade" but to date I have not suffered any "strange" events.