Okay first off lets keep this friendly cause i know a lot of people get touchy on subjects such as these.
So we've all heard the rumors of the Z/28 engines, ironicly we're looking at "the big three" we've got the LS7, the LS9, and seemingly everyone's favorite, the LSA. Me personally dont favor the LSA and with the overwhelming fanbase for it i was wondering who else might agree with me. For discussion purposes i'll list my reasons as to why i do not favor the LSA...
1.) It is a supercharged LS3, which nearly every aftermarket company and private owner seeking performance has already done thousands upon thousands of times.
2.) If all aftermarket companies (now including the new Yenko i guess) are going to be offering supercharged LS3 Camaros, why would i want a production model like that? It most likely be less powerful, cost more (Nickey Stage 2 is going for $40,000) and innevitably the aftermarket Nickeys and Yenkos will be rarer, more collectible, and more valuable anyways.
Warranty
3.) Why use a supercharged 550hp engine when there is an N/A 550hp engine available? Despite rumors of it being terminated (yet to be seen as its still strongly supported in the Z06)
Warranty and driving manners.
4.) Why not just add the LS9 anyways? Top of the line Corvette engines have been available in the past through COPO and other various sources.
Sounds good to me! 
5.) An LSA powered Camaro would basically be a re-badged CTS-V, and isnt that exactly what everyone wants GM to get away from these days?
I don't see how you could say that. While the platform is roughly the same the exterior and interior look nothing like the Cadillac.
6.) The LSA is the only engine out of the three without forged internals = weaker equipment
LS3 doesn't have forged internals does it?
7.) Why use a 550hp supercharged LS3 when you have a 663hp supercharged LS3 available?
Once again, sounds good to me.
I may think of more, these are just the issues i could think of on the spot...