So I picked one up today to try it out. Imagine my good surprise when the ODAC worked with it. USB digital audio out does not work with the stock Nexus 7. Even if it did, there's no micro SD card slot for expanding the memory. So for someone looking for a 7" tablet with good specs at a good price that does USB audio, this is quite the deal at $150.
More discussion about it (there are some people buying and posting impressions of it) at slickdeals: http://slickdeals.net/f/6047392-Sero-7-Pro-will-be-available-in-Walmart-Stores-starting-May-24-for-149-lite-version-for-99?