There is a new Treo update out for Cingular users. This was not a painless update to install. In fact, it took several failed tries and multiple hard resets, so be sure you have a good backup before upgrading.
The good news: Amongst the enhancements in version 1.17 is improved Bluetooth support, including the publishing of extended status information. This means that the Treo can finally publish signal strength (which my car displays in the dashboard). Battery life is still not published, but that is less important.
The bad news: Within the first 30 minutes after installing the update, my Treo hung twice. So don’t expect reliability to improve.