So I said 3.1.1 would have some limited Spotlight functionality but it would be disabled by default. This is true, but it has some flaws in it so I don't even really want to talk about it. The other problem is that the Spotlight importer itself (the piece that sits by itself and is loaded by Spotlight to read the files) wasn't included in the 3.1.1 due to an oversight. So let's just forget about 3.1.1. :-)
On the positive side, later tonight I will be releasing 3.1.2b1 with full Spotlight support, enabled by default, with the importer included. So if you want to try it out I invite you to check back here later tonight (or tomorrow for the more international users) and grab that. It will also fix the nested-journals-appear-as-locked bug that sprouted up in 3.1.1 and add a few preferences.