The Temple of the Jade Serpent is the first of many dungeons we'll be encountering in
Mists of Pandaria, and it's currently the only one open and available on the beta servers. The dungeon is fine at level 85, and if you've managed to level through the Jade Forest and hit level 86, there's a wonderful guy at the front entrance (pictured above) who will sell you a variety of items. These include higher-level bandages, any glyphs you might be missing, and
Tome of the Clear Mind,
Mists of Pandaria's version of Dust of Disappearance for those level 86 or higher.
If nothing else, I'd recommend popping in here just to visit Flaskataur, say hello, and purchase a few things. But that wouldn't be anywhere near as fun as running this starter dungeon. Fast, precise, and to the point, Temple of the Jade Serpent is nothing like the sheer length of Zul'Gurub, and much more like the shortened length of dungeons like Vortex Pinnacle, minus the travel time. In short, it's perfectly ... well,
short!