The integration ofSolaris is going to upgrade NTP to version 4. You probably would care if you're building the ON consolidation or if you're really interested in running NTP version 4.
PSARC/2009/244 Upgrade NTP to Version 4
4669914 Solaris should update to Version 4 of NTP
is a Flag Day for incremental builds.
I also warned you about a problem I experienced with Solaris Express Community Edition build 116.