SPARC died the moment every developer had a good enough x86 desktop running a Unix flavor (and Sun decided it'd be happy not to build desktops anymore). At that point, we cease to imagine deploying our stuff in SPARC. We test on x86 and make it run well on x86 before it gets compiled for SPARC.
At that point, unless the SPARC hardware has some definitive cost/performance advantage, we'll buy x86. SPARC is for legacy.
Same applies to POWER, BTW. How many new apps have you seen in the past 10 years that were designed for POWER?