I can count on one hand the number of times I've had to use an optical drive in the past 5 years. I'm guessing most of us are in a similar situation. For those instances, I pull out an old external USB blu-ray player.
Optical audio I/O. Many people might not know this, but you could actually plug in an optical S/PDIF cable into your Macbook Pro, on both the "microphone" input and "headphones" output line, to get digital audio in and out.
The top level commenter was not talking about an optical drive like CDs or DVDs, they were talking about having optical audio connectivity through a TOSLINK mini plug.
Ah. I used to plug my old original Core 2 Duo MBP into a 5.1 system using a mini TOSlink cable, but since HDMI started doing surround audio I haven't had a need for optical audio connections. It was cool seeing a LED inside the audio jack, however.