I have a project for it
I'm working on a new way to digitize video tapes. Essentially I'm trying to get the raw signal from the video heads and then process it later. Gigabit Ethernet, even if it's just connected to USB2 could give more than 30 Megasameples per second which should be good enough for most consumer formats.
The Pi would then interface with an FPGA with some extra RAM essentially used as a FIFO.