Earliest date on the HW manual is late 2013.
This barely belongs here. It is not part of the Catalyst 65xx plug compatible group. Modules are half width resulting in an over-all much more compact chassis. Picture below is a plug-in module for the switch [not shown].
Newer devices use virtual output port queuing. Last of it's breed, like the 6500, this is an output port buffered design. FPGAs host 8 ports each and have 192 MB of buffer RAM. This is strictly partitioned between a small input buffer and a large output buffer. The switch design overcommits the backplane BW by 2:1 to get 16 ports per card. If you use half the ports you can run in 1:1 mode and then each port has 48 MB of output buffer. The port cards come in lite and heavy configurations to provide varying amounts of TCAM and thus route table size.
Cisco has an extensive white paper  to make the case that the 6880 provides Investment protection. With little doubt, the 6880 is the insurance payout on the investment protection promise of its precessor the Catalyst 6500. There is software and feature compatibility that the 6880 inherits from its parent.
But how will the 6880 provide insurance for today's purchaser looking forward? The future is, in general, hard to predict. But here we have six years of product history to provide hindsite. While there is promise of future capability with extra fabric interconnects to each slot, no new line cards to use them have emerged. Support for new optic modules like BIDI is not available. 25 Gb/s and 100 Gb/s interfaces, also not available. We are here with our insurance policy in hand asking to see the Cisco adjuster.