I had "maxed out" daily rep on stackoverflow yesterday night (Pacific Daylight Time) -- except for acceptances, as usual. (i.e., 00:00 to 07:00 or so, UTC).
Then suddenly this (PST) morning I noticed I'm getting rep again for upvotes I'm receiving on my answer. On my "reputation" tab I clearly see upvotes received 6 to 9 hours ago (midnight to 3 AM PST -> 7:00 to 10:00 UTC) with no rep gain, but also upvotes received 4 hours ago and later (4:30 AM PST and later -> 10:30 UTC and later) which do indicate rep gain. What's up? I hadn't heard of impending rule changes wrt the daily rep limit (only of one impending change wrt the weight of upvotes on questions) -- is it a bug...?
Edit: as the accepted answer makes clear, there were indeed rule changes (for the better, it seems;-) - and indeed my daily rep seems to have maxed out again now (at the nicer new level;-).