I'm pretty split on this one right now, as while I personally like Sony's design and Build Quality, I've ordered the Astak for the additional formats supported and the avalibility of other firmwares
Back to the original question, Both the Sony and the Astek are going to be available in retail, and while Sony currently has a Higher Brand profile then Astak, better pricing or promotion by a few retailers could really push up Astak's visibility.
So, its going to be a bit of a toss-up IMHO, until we can see how widley available both are going to be, and any future promotions.