Kudos to reader Rick Malambri (@RickMalambri), who alerted us to the following:
...there is a work around for Sculptris as well as Sketchbook Pro. If you had previously installed the latest Intel HD drivers (which everything ran fine on), and then you updated your surface with the latest firmware/updates, it overwrites the HD drivers, which causes conflicts with a some software (this includes SBP and Scultris). To fix this, just reinstall the latest HD drivers from the Intel website and everything should be back to working perfectly again.
PS: once you install those Intel drivers, Microsoft's update will say there is a new update to install. DO NOT install it, as it will revert back to old drivers and cause the issues again.
Hope this helps!!
I installed it just now and confirmed that Sculptris runs again. And, even better, the driver allows you to enable canvas rotation in Sketchbook Pro. This latter crash bug sent us into a bit of a panic Friday!
UPDATE: Due to the nature of this site, I'm forced to install and uninstall more software than is wise. Can't say for sure whether that or one of Microsoft's latest round of updates (including today's firmware update) may have caused my Surface Pro to revert to older graphics drivers once again keeping Sculptris from launching.
I downloaded and installed the May 10, 2013 (188.8.131.52.3165 or 184.108.40.20665) driver from the Intel download center and Sculptris runs again.