Our industry is clearly shifting from a CPU with fast single core to a CPU with lots of individually slower core. This is particularly true with Sun and its Niagara offering.
Despite the trend, javac in JDK6 is a single-threaded application, which means it cannot take advantages of modern multi-core CPUs. And we can only expect this pain to get worse as the shift toward multi-core spreads further.
So this RFE is to request the compiler team to introduce parallelism to javac.