I'm not running the GM yet but consensus seems to be that it will show text messages while the phone is connected in the cradle, locked and that you have the notifications to "Alerts" style and "View in lock screen" is turned on. Beta 4 worked that way for me. I lost email messages in Beta 4 as well. There could be another BMW BT s/w update that brings all of MAP functionality back as well. Disappointing to say the least.
Current - '11 e92 M3 SG/FR ZCP|ZCV|ZP2|2MK|494|415|6NR|752