I am pretty sure I am not the only person who doesn't know much about the LS engines, so I went ahead and researched it, hopefully someone learns something.
As far as I know the 2010-2013 use the LS3(manual) or L99(automatic):
Introduced on the 2008 Corvette, the LS3 brought LS base performance to an unprecedented level: 430 horsepower from 6.2L (376 cu in) - making it the most powerful base Corvette engine in history. The LS3 block not only has larger bores than the LS2, but a strengthened casting to support more powerful 6.2L engines, including the LS9 supercharged engine of the Corvette ZR1. The LS3 is offered in the Pontiac G8 GXP and is also the standard V-8 engine in the new, 2010 Camaro SS. The L99 version is equipped with GM's fuel-saving Active Fuel Management cylinder deactivation system and is standard on 2010 Camaro SS models equipped with an automatic transmission.
From what I understand, the LS4 is slower.
There is no LS5.
LS6 is similar to the LS1, which is older than the LS3, L99, LS4 and LS7.
LS7 is the largest engine Chevrolet has (I believe) and its the one that is being mentioned here:
A legend in its own time. The LS7 is the standard engine in the Corvette Z06 and its 7.0L displacement (427 cubic inches) makes it the largest LS engine offered in a production car. Unlike LS1/LS6, LS2 and LS3 engines, the LS7 uses a Siamese-bore cylinder block design - required for its big, 4.125-inch bores. Competition-proven heads and lightweight components, such as titanium rods and intake valves, make the LS7 a street-tuned racing engine, with 505 horsepower. LS7 engines are built by hand at the GM Performance Build Center in Wixom, Mich.
The LS9 is the monster used on the ZR1.