1) It doesn't support battery backup games! How sucky would it be to want to take Phantasy Star on the go and then not be able to save? Maybe they'll release one with some battery-backup games and through some light tweaking we can get that support too.
2) Compatibility is "somewhat" lacking (and we have yet to hear of anyone successfully improving it, though there are many theories as to how to do so)
3) It would likely cost more than a Nomad to get the whole thing up and running probably. And no matter what anyone says about the Nomad, it had fairly good compatibility and a fairly nice case (with 6 button support!) - unless you can get in on one of the PSone screen deals mentioned elsewhere
Anyway, until at least one of the first two (and both would definitely be nice) is resolved, I'm a bit dubious about using it and calling it a replacement for the Nomad. Just my two cents on the thing.

