we have set up SSL on dhis2.org and apps.dhis2.org to get a more realistic testing environment.
This exposed an issue with older wget versions (1.12) related to certificate handling. If you are seeing problems related to certificate not matching host name or similar you can append the --no-check-certificate flag or simply use curl. Examples on getting the latest stable release, and getting the latest build:
wget -O dhis.war stable.dhis2.org --no-check-certificate
wget -O dhis.war trunk.dhis2.org --no-check-certificate