Just a quick note that OpenNMS version 1.7.4 has been released. This is the next developer/unstable version that will eventually become OpenNMS 1.8.
This is mainly a bug fix release (as 1.7 is getting close to being a release candidate for the next stable). Maps are now mature enough that they are enabled by default. Also, the installer has moved to using LiquiBase to handle database upgrades. While this will make it more robust, be extra careful when upgrading for the first time, and as always backup your DB before starting.
We hope you find it useful, and if so please tell us about it.