The 2.0T's are Direct Injection motors.
There is a low pressure pump in the fuel tank as usual, but a High Pressure Fuel Pump is driven off the intake cam and supplies the 2000psi+ of fuel pressure to the FSI rail for the injectors.
That pump uses what you might call a "flat tappet" design, and is subject to wear. There is a warranty on most fuel pump follower/cam issues till around 110k or so IIRC. Basically the maintenance involves removing the HPFP and replacing the fuel pump follower at regular intervals to prevent cam wear and eventual intake cam replacement. It's not a hard procedure, and isn't much longer than an oil change.
Here's a PDF on the procedure which I've been using for years now:
http://freepdfhosting.com/8791e81dac.pdf
If not taken care of, eventually the fuel pump rod will punch a hole in the follower, then score your cam and eventually break that, which usually causes the cam chain up top to snap and well, ruin everything.
Also, FSI/TSI motors are subject to excessive carbon buildup on the back of the intake valves. This tends to affect cars that are driven like a grandma, and short trips. The cars that are driven like a red headed stepchild and for longer periods seem to have less issues in this area.
The 1.8T is much simpler in design, and tradition port injected motor.
Parts are cheaper ect.