Is it possible to download PSVita games to an imported device without using a Japanese account? That is, before its launched in EU for example.
I can confirm the US and EU stores are not live. Attempting to access the PSN store with a US profile on a Vita as of 12/31/2010 will encounter a cannot connect error until they are launched along side the Vita rollouts in those markets.
I doubt that any other countries will launch their stores prior to their country's release. As the Playstation Vita has not officially released in countries other than Japan, I highly doubt this is possible.