The gap this page is about
The last beta client is 1.60.1.70009, pushed on 24 September with Blizzard's development notes attached. Four days on, it is still the client. Ask any build tracker what changed since and the answer is nothing, because the number it watches has not moved.
Meanwhile the data did move. Blizzard ships corrections to a running test
through a hotfix cache rather than a client patch - the file the client
downloads on top of its own tables, DBCache.bin. Nothing about the version
string changes when that file does. It is the same mechanism live WoW has
used for years; what makes it worth a page here is that during a five-week
beta it is doing most of the work.
How you can see it from outside
You cannot read the cache directly, but you can watch somebody who regenerates from it on a schedule. An open-source simulator project pulls the beta data off Blizzard's CDN together with the current hotfix cache and opens a pull request whenever the output differs from last time.
Between 26 and 27 September that produced four runs, all of them labelled with the same client build and a different hotfix date. If nothing had changed, there would have been nothing to commit.
What moved on the 26th: a handful of item records, including a weapon from Classic - the Gizmotron Megachopper - whose random-property budget was adjusted, and new entries in a high ID range that did not exist in the previous run, among them a shield called Painwalker Buckler.
What moved on the 27th: three more Classic items touched (Humbert's Helm, Jurassic Wristguards, Watchman Pauldrons), five items added that were not there the day before - Nature's Cull, Wail of Death, Mark of the Red Flight, Eternally Frozen Band, Snapped Branch Wand - and four effects that had been sitting in an "unresolved" list dropped out of it, which is what happens when the data behind them finally arrives.
None of that is an announcement. It is the difference between two regenerations of the same build, which is a weaker claim than a patch note and a stronger one than a rumour.
Why it matters for everything else you read
Three consequences, and the third one is ours.
A build number is not a date. "Unchanged in 70009" and "unchanged since the 24th" are different statements, and the first is regularly written when the second is meant. Two trackers can honestly disagree about the same week because one reads files and the other reads version strings.
A fixed bug may leave no trace. Blizzard's known-issues list is edited in place rather than reposted, and a server-side fix does not bump anything. So the absence of a note is not evidence that a problem is still there - and a newer build number is not evidence that it is gone.
Our own talent snapshots have this blind spot. The calculator here is built from files read out of a client and labelled with that client's build. A talent changed by hotfix would not show up in the next comparison, because the next comparison happens when a new client appears. We have read 1.60.1.70009 and we will read whatever comes next; the days in between are not covered, and saying so is cheaper than being caught by it later.
One claim we are deliberately not carrying
Since the 25th there has been a recurring report that spell base damage was cut across the board, without a note. We have not found a Blizzard reply in any of the forum threads raising it, and the change is not in the 24 September notes.
It is possible - it is exactly the kind of thing this page says can happen invisibly. It is also exactly the kind of thing that gets claimed in a beta week when everybody's numbers are moving for several reasons at once. Until somebody puts two readings of the same spell side by side, it stays off the data pages here.