The new Apple MacBook Pro does not feature an optical drive. Apple has also removed the Ethernet port. This means more adapters.
And as expected, the company has started selling a Thunderbolt to Gigabit Ethernet Adapter and it is priced at USD 30.
Apple describes this product:
The Apple Thunderbolt to Gigabit Ethernet Adapter lets you easily connect to a high-performance Gigabit Ethernet network. Small and compact, it connects to the Thunderbolt port on your Mac computer and provides an RJ-45 port that supports 10/100/1000BASE-T networks.