Update: The initially reported June 28th date is actually the release/on-sale date for the two new lenses according to digicame-info, the announcement should happen earlier.
According to digicame-info.com, Nikon will announce their new 24-85mm f/3.5-4.5 and 18-300mm f/3.5-5.6 lenses on June 28th, 2012. The previously rumored June 15th announcement will probably be for the 70 million Nikkor lenses milestone.
Here are some new Nikkor AF-S 24-85mm f/3.5-4.5G ED VR lens specs:
