WorldWide Tech & Science. Francisco De Jesùs.
It last a few hours since it was reported before S Voice app leaked has been locked by Samsung until you get an official launch of it. For Europe on May 29th and for North America this summer.
S-Voice is an interactive voice assistant agent. Samsung appears to have locked down S Voice and prevented the leaked APK from connecting to its servers. This means any query sent to to S Voice on a non-Galaxy S III device will return a "network error" message. See picture below.