Yes, I would believe he is next in line both for being the nr 1 target and taking over the position as the "sheikh" of Al-Qaeda.  There are strong indications though that Al-Zawahiri has been running most of the operations almost from the start and that OBL have been more interested in the iconic part of being an Islamic leader.

Still I have to add that until more evidence is put forth I am sceptical to the accuracy of this alleged information.
 

Bitsofnews.com Giving you the latest bits.