From Ben and Mena

Maciej Ceglowski has built a prototype for a semantic search engine. To adapt it to function as a Movable Type plugin, he needs sample content that he can test against.

If successful, the search feature would let you do a keyword search, and get back relevant results even when there was no exact keyword match.
If you use Moveable Type, and you'd like to help out, send him some content.

Maciej is using latent semantic analysis to enable local search beyond keyword indexing. Sounds like an ambitious and exciting project.