The roadmap for 9.2 that we had seen previously showed SP 1-4 and an early ’08 release for 9.3. As we know 9.3 has been pushed back to Q3 (probably around the time of the UC) but keeping with their plan for quarterly service packs and updates ESRI announced that SP5 will be released later this month. There will be Vista specific fixes, geoprocessing fixes, and plenty of others.

Patches and Service Packs – ESRI Support