Hiya everyone, this is my thoughts on Skarner in the new S3 Jungle, and how I think he will fit into the game with the new items.
Generally, Skarner is an excellent jungler, in both Season 2 and now into season 3. With AOE junglers being predominant in 2, he excels in the Jungle, easily able to clear out minion camps with ease. His Q deals physical AOE damage, and once charged deals additional magic damage, and since its on a short cool-down, its a spam spell that makes his clear time pretty fast when compared to a lot of Junglers in the game. His W spell, is his second most important, as it gives him a damage blocking shield that boots his attack speed and reduces hi Q's cooldown even more thanks to his passive. When I jungle I always max Q and then W, or if I find that I need a little extra MS to catch up to opponents, then I max W and then Q. This is especially effective if you're ganking players without boots, or they generally have low movement speed, as even the 25% slow off of his Q will allow you to stick to them unless they blink or flash away.
That said I Start with Q, W, W, Q, W, R, then I rank up Q and W, and then E, ranking up R whenever possible. To me his E spell, is kind of useless in the jungle. "Wait a second!" You might cry, "His E spell heals him! Thats useful, especially since the new Jungle camps deal more damage and are tougher to kill!"
To that I say "While that may be true, the heal is paltry compared to amount of shield gained with each rank of his Crystalline Exoskeleton." In the jungle, its not how much you can heal early game, its how much damage you can deal, and how much damage you can mitigate. Aside from WW and Fiddlesticks, dealing as much damage as possible and shielding incoming damage is the name of game. You might heal 40HP with a rank one E, but if you rank up your shield, you can gain an additional 60 'free' hp as well as a quicker attack and movement speed steroid. With that said steroid, you can AA more, which means more Qs which means more damage, which means quicker clearing times and less health lost overall.
Now I've mained Skarner for a long time in the Public server, and I've spent a lot of time in the PBE jungle just working on my clearing times, and I've found that maxing Q and E gives me the fastest clear with the most amount of HP for ganking and the like. Besides, early game the damage from E is minute compared to the damage and additional slow/MS from a higher ranked Q or E, making ganking a lot easier and less risky.
Starting off with the Machete and 5 pots, I've managed a 3:45-3:50 clear time consistently, moving from wolves, to blue, to wraiths, back to wolves, red, and then wraiths again. And by clear time I'm talking level 4 under four minutes, giving you enough blue and red to gank middle, top, or bottom lane if the opportunity arises.
After the wolves, I evolve the Machete into the Spirit Stone, which increases the damage you deal to jungle monsters by 20% as well as the additional 10 true damage per AA and a nice upgrade to health and mana regen. Ninja Tabi are my next pick, as the armor and passive make it easier to clear the jungle monsters with more HP. Sheen is the next time, and I upgrade the Spirit Stone into a Spirit of the Ancient Golem, which gives great jungling benefits, 30 armor, and 500 Hp and that lovely, lovely thing called Tenacity. Besides, at 2400, its a good early game tanky item that gives Skarner a lot of HP, a good amount of armor, and mana/hp regen.
The rest of the build is as follows:
Spirit of the Ancient Golem
Ninja Tabi (Upgraded with the Furor Enchanment. More movespeed? Yes please.)
Iceborn Gauntlet.
Runic Bulwark
And the final two items are situational. I usually grab Mercurial Scimitar and Maw of Malortius, because this gives you a very balanced build between HP, AR, and MR as well as plenty of damage. I go for attack damage vs AP on Skarner because of his excellent scailing with bonus attack damage on his Q, and since you're able to spam it every two seconds or less, it can quickly add up. The Maw passive has saved my bacon more times than I can count, and there is nothing like watching a Veigar drop his stun field only to MS (QSS) out of it and tear him a new *******.
Now many people might question the Iceborne Gauntlet. Why not Trinity Force? Well, Trinity Force is very nice, but it is also expensive. Iceborn Gauntlet gives you everything you could want with Skarner, 60 Armor, 500 mana, 15% CDR, 40 AP, and not to mention an amazing passive.
Trinity Force allows you a proc that deals 150% of your base attack damage to a single target. IBG gives you a proc that deals 120% of your base attack damage in a about a 300 unit sized AOE that also slows for 35%. If you strike two or more targets, its already dealing more damage then the TF proc. This also allows for a supreme permaslow that is really only escapable through flash or you getting CC'd... (Hence the Merc QSS active). If you somehow miss your Q, then your AA will slow them.
This also allows you a lot more leeway in your potential to CC opponents, as you get the proc by engaging your Crystalline Exoskeleton, and when you hit them with your AA it slows them, allowing you to get off an un-charged Q on them, and by the time the slow has worn off, your Q is charged, and you can slow them conventionally. (Well, conventionally with Skarner. :P )
This build isn't the cheapest one, but its one that I've found to be very effective on him. ****, I went 23/8/17 with it. It is a very *solid* bruiser build that allows for a lot of tankiness while still maintaining enough damage to be a significant threat in teamfights.
Overall, I think that Skarner will be a top-tier jungler in S3, and I wouldn't be surprised to see him a top pick as well as a top ban. I also like the new Jungle because Lee Sin is no longer in the God-like tier by himself. 
Tell me what you think.