The SA technology is patented by Yamaha so that no one else can use it.
However virtually all large sample library VSTs (And others) have had plenty of these types of voices for years.
The Wersi OAS 7 sound system also has the capability to perform the same effects, however as of yet Wersi has not released any voices using it. (It currently costs a lot of time and money to develop these types of voices; even the simpler SA voices are limited in the number that are available)
To show what could be archived in the future; there are some simple ones at http://www.sonic-core.net/de/products/soniccore.html and http://www.soundfonts.it/?a=read&b=25 with another interesting technique here http://www.samplemodeling.com/en/demos.php

Hope this helps

Bill