The images showed up on Monday on TonyMacX86. The card shown in the images is a Broadcom BCM94360CD PCI-E mini custom combo WLAN+Bluetooth card.
That card, it appears, supports IEEE 802.11ac ? a wireless standard also known as "5G" or Gigabit Wi-Fi. 802.11ac allows for speeds up to twice as fast as 802.11n, the preceding standard.
The fifth-generation of wireless protocol, 802.11ac sends data over two channels, with each carrying single link speeds of 500 megabits per second. In theory, the standard should produce speeds of up to 1.3Gbps.
via Tom's Hardware
Code previously discovered in the OS X 10.8.4 Mountain Lion beta build tipped off observers to the possibility that Apple would soon be bringing the 802.11ac wireless protocol to its Mac lineup, and the pictured card, if valid, would seem to verify that.
Apple was also rumored earlier in the year to have struck a deal with Broadcom, the maker of the pictured card, to put 802.11ac chips into its 2013 Mac lineup. In January, job listings on the company's site revealed that it was looking to hire experts in the new wireless standard.
Apple is widely expected to show off refreshed versions of its Mac lineup at this year's Worldwide Developer Conference. These new Macs may feature the next generation of Intel processors, dubbed Haswell.
The company is also expected to show off previews of the latest version of OS X and its iOS mobile platform, but Macs are especially anticipated, given reports of shortages in certain lines ahead of the developer conference.