Destiny is going to be offline on Thursday to prepare the game for the update. You must survive real life starting around 8:00 a.m PT (11:00 a.m. ET). Tomorrow's maintenance is scheduled to end by 12:00 p.m. PT (3:00 p.m. ET).
You should not be able to see some visible changes as a result of the planned outage however the back-end work will "pave the way for the progress".