A new firmware version for 2011 Xperia models was recently certified by PTCRB. The new firmware version (4.0.2.A.0.61) is believed to mainly bring bug fixes. This includes a fix for the restart issues that some people are having on certain phones like the Xperia neo V. The roll out of this firmware is expected in the New Year according to this forum post.
Despite this eMobile’s Sony Ericsson mini (S51SE) has already received this update in Japan. This update is still Android 2.3.4, so it won’t bring the new UI features we saw in the recent leak. We’ll bring you more news as we have it.