The way I've seen search implemented in some of the newer forums applications leaves very much to be desired.
Judging by the nature of these platforms, I think Stack and Askbot have the best search implementations, which is one that has auto-completation matching topics as a user types in a question or when the user is typing in a search string.
What will it take to implement something like that here?
I think so too, the search-as-you-type would be really helpful to avoid duplicate topics.
Spirit uses an app called haystack, they even have an example on how to do it. So I think it'll be relatively easy to do.