According to a report from ASCII, a SCEJ rep has apparently said that downloading files from a 3G version of PlayStation Vita will be initially capped to 20Mb. The Sony person did state the size could change in the future, though. It also said to the site that it's providing developers with support with online technical limitations when asked about the 64kbps upload and 128kbps download, and also reiterating that both Wi-Fi and 3G versions of Vita will be able to purchase from the PS Store.
Vita's out on December 17 in Japan and early next year for the US and Europe. Thanks, Andriasang.