Well, it also seems like solid state drives will get there soon. You already can get at least 64 GB on a thumbdrive and iPod Touches are up to 32, right? No reason why we should see 128 and up in the next couple years.
Maybe the interim solution, until cellular networks and devices take over, will be all your music stored on a large thumbdrive with a separate tiny device handling playback of files form that external media. If the Sansa Clip or iPod nano can fit playback and browsing functionality into tiny packages, why couldn't similarly sized devices interface with external media? For that matter, maybe that's something rockbox could do in the future.
But we stray from the topic

So Gigabeats are too small. Am I left with iPods or nothing? I was expecting more options.