The point at which I regressed browser startup time in the Firefox 2 Alpha 2 was about the same point at which I started keeping a very keen eye on Tinderbox. Thus, a Tinderbox status Microsummary! Microsummaries are a hot new feature in Firefox 2 - basically a bookmark with a label that periodically updates. This Tinderbox Microsummary will show "OK" or "{#} Burning ({hostnames})" for the tree that you bookmark. Support for orange trees is not there yet.
You can install it here.
Also, here's a snippet of XSL for allowing your generators to display themselves, as they traipse about the internets.