Apple has released Java for Mac OS X 10.6 Update 2 [1] for Snow Leopard users, updating Mac OS X's Java SE 6 to 1.6.0_20 and delivering "improved reliability, security, and compatibility for Java SE 6." The only details given revolve around security fixes [2], so it's probably worth downloading this update even if you don't anticipate using Java applets much. The update requires Mac OS X 10.6.3. (Free, 78 MB)
[1]: http://support.apple.com/kb/DL972
[2]: http://support.apple.com/kb/HT4171