I don't have any more information on the upcoming confirmation hearing for Brock Long other than this announcement of the meeting time and those appearing as confirmands. Candidates for confirmation will be appearing before the US Senate, Homeland Security and Governmental Affairs Committee
I did read another article decrying the vacancy at FEMA for the administrator's position, with the nation going into the hurricane season. I would have to note that I recall that is was about mid-May when Craig Fugate was confirmed, so they are not "way off" on the timeline for getting someone in place to lead FEMA when compared to the previous administration's timeline.
Remember, it is after all, best for all electeds to have leadership in place so they have someone to blame if things go poorly. An "acting" is a poor substitute for someone nominated by the president.