Be sure to cover both the front- and back-mountains as well as the three peaks!!!
I brought along my D70S + 17-35mm + 50mm in the autumn of 2005. How I wished I have a telezoom. Don't worry about a few lens setup instead of a superzoom; the pace in Huangshan is such that you don't rush about seeing things. Everything is at a snail's pace. Hopefully, you have at least 2-3 full days to cover most aspects of it.
It was a 50-50 decision on the tripod but I gave that a miss. But do bring along a polarizing filter as well as a 2-3 stop GND. Plus a backpack; not a sling or shoulder bag. My whole setup was less that 2kg.
On a side note, in Mt. Huangshan, remember not to take pictures and walk at the same time; some parts are really steep and dangerous. Please note this very important point.
Lastly, enjoy and do remember to trek with care.
P.S. I would wish for a Fuji S5 Pro if I were to do it again.
This place has lots of picture taking opportunities. It depends a lot on the weather condition at the time of your visit. Ideally, it will be great if you get the chance to stay overnight at one of the hotels up there. If so, you should be able to get some interesting shots during sunset/sunrise and less crowd.
It is likely that there will be A LOT of tourist there, so you may not find a tripod practical (unless you plan to do sunset/sunrise). The paths and stairways at the top are quite narrow and the local visitors think nothing of bumping against you to get pass. Use a back pack. Do bring a good wide angle zoom and a mid range zoom or primes. You probably won't need anything more than 200mm. Bring a flash gun for flash fill as there are some grottoes like tunnels.
There is a very long cable car ride to bring you up there. But there's quite a lot of climbing up/down on steps along the ridges to get to the various peaks. So good shoes, hat, sunglasses are needed.
At the end of the day, there is a mad rush to take the cable car down, so the queue can be pretty long and chaotic. I decided to walk down instead. Takes about 35-45 mins (I think) brisk pace, but not so many things to shoot during the walk down. If you got bad knees, forget about walking down.