According to information published by Francisco Martín García, we can look forward to the Public beta of Windows Live Essentials 2011 around the 24 or 25 June 2010.
The build that the Windows Live team is preparing to release as Beta has the version number 15.3.xxxx.xxx. The current version is 15.3.2838.0614, but this is an internal beta, so the public beta is sure to have a higher version number. There have also been rumors that the public beta might get the version number 15.4.xxxx.
The original planning was to release the public Windows Live Essentials beta some two weeks earlier, but apparently there we some internal problems causing the current delay in order to address them. We will keep you updated as soon as we receive more information about the coming public beta.