If it was a pretty non-commercial effort (eg, someone making new boards that bolt into an existing empeg chassis but with, say, SATA, gigabit ethernet, etc) I seriously doubt anyone is going to notice/be bothered. There's no money in chasing it.

If, on the other hand, you were trying to sell a new product based on code which you didn't have the rights for or source to, then that'd be different....

Obvously, I am not a lawyer, this is just my personal opinion

Maybe an OMAP3530 (the variant with 256MB stacked DDR?), a little FPGA to hook it up to PATA and ethernet & probably the display too as chips these days don't have the greyscale LCD controllers that they used to have... looks like it has a decent external bus interface that could be used to hook high bandwidth stuff up to. You could even have the HDD as an option and just use SD cards as main storage.

Hugo