What can slow down/How can I speed up the pre-kernel boot steps?
The boot selector scans all possible boot devices, including network, firewire, and USB devices.  Try disabling WiFi, unplugging everything, resetting PRAM (like cksum said) and then rebooting again.  The fewer choices the boot-loader has, the faster it will load.  The ultimate speed up, is to go into System Preferences -> Startup Disk to select the desired partition.  It sounds like that is not what you want, but it illustrates the process.