Personally, the jungle changes almost every season right now anyway, in some respect. The last couple changes have been almost invisible ones, meant to push junglers into ganking lanes. For Riot to add more camps would be redundant...and at the same time, it would probably be a bit easier for them to balance were they to have more material to run with.
Jungle changes and balance are never easy, and Riot makes it even harder on themselves by making everyone who can't get a kill before lv 6 pretty ill-suited or the role...hence why you don't see a lot of Fiddlesticks or Shyvanna in the jungle anymore - unless you're already really good at playing them, they're nowhere near as potent as other junglers that gank earlier instead of farming to 6.
And we're also talking about the 100-to-0 in 0.5s meta...so tankier junglers with lower clear times are also less frequently used. That makes me sad, because those guys (specifically Naut and Gragas) were the only ones I was decent with in the jungle, but they just fall behind way too easily with the current jungle iteration because by the time they get their first clear, the enemy has likely already cleared, ganked a lane, and went back for their first item.
Before I end up digressing too much, I think the thing that the jungle most needs right now (though this is a very biased opinion) is an item that gives tank junglers a little more AoE clear to keep them relevant.
"But Reyn, HINDERHULK!!!"
That's one item, and generally by the time an average tank jungler can buy it, their opposing AD dps jungler will already have rushed a tiamat and went back to complete their jungle item of choice...or played Korean cheese Twitch and got their jungle item after setting your bot or mid lane 1-2 levels behind, but the main thing is that first part. Tiamat being available early on to these types of AD/DPS junglers is one of the very key factors in how people like Jarvan, Warwick, Shaco and Yi get ahead of the rest of the pack very quickly. The other is in their generally earlier ganks. Allowing tankier junglers like Sion, Naut and Gragas to have something to AoE a bit quicker would mean they can countergank on time, and be more relevant.
As for mage junglers...they're a lot harder to balance, because they're a lot harder to pin to a more general reason they fall behind. Fiddle is slow, but one of the healthiest junglers. A change to make him faster would make Diana, for example, one of the strongest champions in the entire game, since she clears pretty decently fast, but has trouble in picking a good gank pre-6. Trying to give her something that allows her to gank better would make Nidalee insane, since she's got decent clear and gank potential, but is really prone to being counterjungled since her early game is not really suited for a 1v1, especially if she misses her spear. Trying to give some item to help her early game will loop it back to making Fiddlesticks literally impossible to fight.
But since tank junglers all suffer from the same generic issue (not being able to clear fast enough to be able to respond to enemy map pressure) they can all benefit from a more general fix.