I was thinking about those three too, but my only problems are
a) none of them use AA's and proprietary batteries are difficult to replace (you could just get rechargable AA's!).
b) CNET hasn't reviewed the yp-t8
c) the u10 is rather pricy
and yes, the u3 is out, or at least on some UK site.
The iriver u10 1gb
the samsung yp-tz8(video one)1gb
or the cowon iaudio u3(is it out?)