Currently, I hardly use Spotlight on my iBook G4 800 MHz. The application launcher capability is what I need most, and I find Launchbar to be far faster than Spotlight for this. Launchbar even does a decent job for many of the searches I need, at the same speed as application launching, but Spotlight search for the same can take very long.
Can't Apple employ the technology used in Launchbar or Quicksilver along with their existing technology to make the searches faster? I know Spotlight is lower because it has to index far more data as it searches inside files. However, most searches perhaps don't need the data that is inside files, but merely the same metadata that is indexed by Launchbar/QS. So, why not have a two-step search: first search the data that is not inside the file and give results as quick as Launchbar/QS, then search inside the files to give other search results?
I understand this may be a non-issue for the latest Intel Macs, and so, Apple may not bother.