Today Linden Labs is rolling out a new server-performance measure that will put regions on "idle" when there are no AVs in a particular region, or looking into a particular region from an adjacent region. For now it's just on the Blue Steel servers but it is expected to roll out grid-wide.
Region Idling FAQ
Discussion thread.
My concern - which has been raised by a few people in the discussion thread and was discussed briefly last night in the KCAddicts group - is what this is going to do to breedables. Right now I'm keeping some live cats in-world (most are in the cattery, but at any given time there are a dozen or so getting milk to sync their breeding cycles.) The region where I keep them is often empty. I could move them to a region that almost always has people in it, but script performance there is not as reliable.
I don't want my cats to get hungry or miss out on their milk! Is this likely to be an issue for KittyCats?