I'm a Diamond Shaco main.
Not to call out anyone else in this thread but, Shaco is NOT just a split pusher / late clean up guy.
Here is the thing. if you build Shaco correctly, late game you can evaporate just about any mage or adc... before they can even react.
summoner spell

Skill Order: Start W... then R>E>Q>W
A lot of people say that it should be R>E>W>Q... but lvl'ing Q drops the mana cost while also ramping your front end damage... and to me, Shaco is all about the front end damage.
Currently... even though you can stay out longer... in the jungle it is more important to quickly get a gank off and then go buy your upgrade.
With the Jungle item upgrade being increased in price next patch... I suggest...
(Don't buy Pots save the 70 gold) Box Red > Smite Krog > Gank Top/Bot > Buy
Smite Red > Gank Mid > Wolves > Smite Blue > Gank Mid/Bot/Top > Buy/Gromp
(Don't Buy Pots, save 70 gold) Box Blue > Wolves > Buy
Box Blue > Smite Grump > Wolves > Gank Mid/Bot > Buy
but until that price increase hits... buy the pots always.
One thing to keep in mind... until you have some damage under your belt... and I'm talking like nearing
or a finished jungle item... Don't do the Raptor camp unless you plan to back and buy after and have smite up... it is just too much hp lose for the gold it gives... also Devour enchantment isn't worth it right now... maybe if you just want to farm for late but I'm finding more raw ad to be better.
Build order is
rushed, >
>
>
>
>
>
> optional last item
After you have
, it is important to use the animation reset correctly...
COMBO #1... Q auto, Shiv,
, Auto, Ignite... will kill anyone even a little low... or start a fight with you in such hp lead that they are in flight mode rather than fight mode... which is good since you are soft as hell.
Also remember that Ulting while stealth'd does not break the stealth... so You can Q in, and while stealth'd, ult so that you pop out of the Q with your clone out if you know you can kill with the added damage. otherwise save the ult to dodge retaliation.
Late game you are a splitpushing god... but you can also start fights for your team. If you have even one other person on your team that can follow you diving in with some cc... you can create massive Chaos...
Q'ing into the back lines and doing Combo #1 on the enemy adc or mage will ether kill them... or leave them at >20% hp and running for their lives... If at the same time as you come out of stealth your team goes in on the enemy, you can win a whole fight even if you die, and you might even live thanks to a good ult.
When split pushing always get boxes down to watch for rotations... or drop them in lane to cover retreat paths...
Don't underestimate ulting in a bush and sending your clone running while you blue pill ether.
Also the option of Q'ing in a bush and then staying in the bush as the enemy runs off trying to find you is a good one.
Along the same lines, Running to a wall then fake Q'ing over fools people a great deal of the time.
When it comes to picking off people in the split push... some thing to never underestimate is what I like to call the "Fadeaway"
Basically when someone walks up an open lane to meet you pushing a wave act scared... turn and run and after a second Q back towards them and don't rush it... you have three seconds. League is a rush game, and after about two seconds they will think you just ran away... they will walk up for creeps, and bam... Combo #1 and you've pulled off the"Fadeaway".
I've got a stream that I show all of this on... if you wish to watch. http://www.twitch.tv/arkangelhfb
Hope this helps and remember... "This will be Fun!"