I got the following quote from Lexar's Director of Global Marketing, Joel Boquiren, regarding the current Lexar XQD memory card situation:
"Due to an unforeseen memory constraint from our XQD technology partners, we’ve had to delay production of the Lexar® Professional 2933x XQD™ 2.0 card until further notice. We are trying our best to minimize the delay as much as possible and are searching for a cost-effective plan for our XQD technology to perform at its best to meet our customer’s’ demand. In addition, we are working tirelessly on the future standard of CFexpress through our efforts in the Compact Flash Association."
Here is some background information I received from "unofficial channels" (these are basically unconfirmed rumors, so please treat them as such):
