We're unable to have the message search functions be realtime right now because the database server can't currently handle the extra load along with the greater load it's seeing from the huge increase in traffic recently.
We've ordered a new database server and the new version of SQL Server, which, among other things, has vastly improved full-text search functionality and performance.
In the meantime, we're updating the full-text indexes afterhours and working on other ways to reduce the database's load so it can return to realtime full-text indexing, and if that can't be accomplished soon, I'll try to move that function to SI's database server, which has tons of excess capacity going unused.