When vanilla Destiny shipped, you were blocked at level 29 unless you got a full set of raid gear. No boots, no level 30, RNGesus be blessed. Now:
10 item slots contribute to your light level (primary weapon, special weapon, heavy weapon, ghost shell, helm, armor, gauntlets, boots, class item, artifact). You won't be chasing one item to get over the light requirement - a good weapon might be what pushes you over. Or a helm. Or a ghost.
A large proportion of the weapons now drop from dedicated loot streams, and in particular quest lines. (For example, all swords come from quests, not RNG.) There are apparently a LOT of quests (most of the new achievements are for completing the high end quest lines). Any legendary weapon or armor item can be ascended via finding higher level gear for that slot, so you can pick what stuff to carry up to that level.
Legendary engrams are guaranteed from the weekly playlist; the Cryptarch sells them; faction packages guarantee a legendary item; the Gunsmith will sell weapons for order from a rotating stock via Armsday. Perhaps most crucially, RNG systems have been updated across the board to watch what you have, and don't, and tip toward what you don't have. This made a huge difference in the drop rates for Crota's End, and is said to have been tuned even further for TTK.
It's the same as the old system in that gear makes you more powerful. It's not the same as the old system in what makes you powerful, or how you get the gear. Bungie has been vocal about avoiding the walls people hit at level 29 in the vanilla game, and have redesigned the loot streams to avoid it with TTK. We'll see how effective it is, but on paper they really are not the same.