Can confirm this is a class 4 card, as there has been numerus speculation...
I am using this card on the new Blackberry 9780, and works fine. The total space after format is 14.8GB.
Transfer rate for a 700MB avi video file via a USB sync cable to my Blackberry was:
Moving the file from my desktop to the memory card:
Write: 4.40MB/second (Average)
Moving the file from the memory card to my dsektop:
Read: 160MB/second (Average)