I think 24/192 is a nice to have, at least given the amount of music MOST people likely have in that format. I have two albums in 24/192, nothing else better than 24/96. I copied some hi-rez to a computer I have that has a cheap Diamond sound card that does up to 24/192 out on coax. Using KS or ASIO, they DID sound damn nice. Getting a nice sound card that offers this is a possibility (for laptops, not sure if there is a cardbus or PCMCIA card that does this).
It's one more piece in the chain, but I'd also consider a USB->S/PDIF converter that handles 24/192, and not limit the DAC's I seek otherwise.