If anyone's still interested, Apple release Aperture 3.4.5 a few days ago. According to Apple:
"Addresses an issue that could cause Aperture to quit unexpectedly when deleting items from a camera or memory card after import
Memory cards are now ejected correctly when using the Delete Items option after import
Includes stability improvements"
I was hoping for some mention of Aperture at WWDC. In vain, alas.