I've not seen such a design yet, but if you don't need that kind of bandwidth for your WAN link (and I guess you won't - but tell me otherwise, and I will certa

I've not seen such a design yet, but if you don't need that kind of bandwidth for your WAN link (and I guess you won't - but tell me otherwise, and I will certainly be a wee bit jealous ;)), you can always just attach a switch with 2.5Gbps port speed to one of the 1Gbps ports of such a box. (Just be careful what you buy if you need VLAN support for those ports/that segment). You probably won't need a six-port variant in that case, which makes cheaper and more compact designs an option. As for 2.5Gbps Ethernet NICs with OpenWrt - I guess it depends on the particular component/NIC. People I know have had rather bad results with 2.5Gbps Realtek NICs on Windows, and I don't know if the Linux drivers fare any better. Unless you really need the additional bandwidth, I'm pretty certain that you will have the all-around better experience when sticking to 1Gbps hardware for now.