This forum post claims that TPv1 doesn't support a serial console http://www.tonido.com/forum/viewtopic.php?t=2535&f=32 (not sure if this is reliable)
I'm not opposed to serial and will purchase the hardware, but I haven't found a reliable guide of how to do so. Information out there on serial access for TonidoPlug v1 seems conflicting. Any leads in the right direction are appreciated.