Yes, each module in the chain acts as a switch (much like Ethernet switches) and as such repeats the signal. Since each link in the chain has ECC, this ensures end-to-end message integrity.
Will the downstream port act as as a repeater i.e. rebuffer the signals (much like an ethernet switch or hub will do) so you can run longer leads etc.
And what would the realistic maximum length of interconnect you could use be?
I guess its a bit late now but its a shame you cant use cat5/6 as the interconnect medium as its easy to get hold of shielded cables which would help with long lead lengths in a noisey environment...
Please note that voltage drops more over longer wires. go!bus is designed for chassis wiring (e.g. the go!bus cables), so you probably won't want to wire a chain from your basement to your second story balcony
BTW, you could certainly create a module which converted the signal to cat5/6. go!bus is designed to be media independent at its core, so there's lots of possibilities there.