i think that never will happen because if they do that there will only be a 50hp diff. in the engines in the 3.0 and 4.8 and thats just not reasonable for the difference in price..just see all the other manufacturers and their suvs like the new porsche cayenne the base one has 295hp and the cayenne s has 385hp thats 90 hp diff. and then take a look at the range rover sport and range rover sport supercharged its a 90 hp diff too....just like its right now in the 3.0si and 4.8i its like a 90hp diff so i think it will stay that way..
just my 2 cents