When upgrading 2.0 sites to latest weekly build - Moodle 2.0.2+ (Build: 20110406) - using CLI upgrade, upgrade fails with the following messasge:
!! php !!
Required minimum version: 5.3.2. Version in use: 188.8.131.52.0
AFAIK, PHP 5.3 is required for Moodle 2.1, thus php 5.3 check appears to be wrong when upgrading 2.0 sites in the same branch.
Logging in as Administrator and performing an interactive web based upgarde, upgrade completes correctly and site is working.