It is important to note that once you choose either gnomish or goblin engineering you can't switch back unless you drop the profession and pick it back up again.
Gnomish engineering has some benefits that will help you with end-game things. These are devices that are both helpful and dangerous to use. The best one that I have seen so far is the transporter. There are two that you can get though I currently only have the transporter for Gadget. This transporter allows you to basically use the city as an alternate hearthstone every four hours. Be sure that if you plan on using this transporter you have a parachute cloak on first though.
The transporter says it's safe 4 times in the discription. I'm not a genius but to me that screams danger. If you don't have the pattern for the parachute cloak get it before you use the transporter. In the many times that I have used the transporter it has only safely deposited me at my destination four times. There are times when you apear to be normal and in tact but are replaced by your evil twin for two hours. At other times it may randomly turn you into a merloc or a gnoll. Most frequently, however, it will transport you to a spot 10,000 feet above and 10,000 feet away from your destination point.
It is at this time that you start removing as much of your armor as possible while you open your parachute. Keep in mind that you mar land on top of a buzzard or a wolf when you fall so don't remove your weapons only your armor so you don't fall too fast and don't have a large repair bill.
You must be wearing your parachute in order for it to open and don't open it immediately or you will run out of time on the fall and it will close before you reach the ground. Wait until you have been falling for a few seconds to open it.
If you plan to use your transporter keep in mind that you may fall onto elite mobs outside of the Zul'Farrak insance so if you are only lvl 35 be prepared to die horribly.
With that I bid you a happy and hopefully safe landing!