The pdf of Catalyst Game Labs' new quick play miniature rules set in the Battletech universe will be available to buy and use July 29th, 2013. The hardback can be preordered at that time and is hopeful to be ready in September.
Also, the price is $39.99 for the hardback and not $44.99 as was shown in the original pdf. They forgot to change it in the pdf when they released it.
Source - the Battletech website and the Battletech forums.