See below for patch notes.
We're getting ready to release a mandatory update for TF2. It should be ready in 10-15 minutes. This is not an April Fools' joke.
Areas of interest:
All crates are now rare-ish drops. Far cry from salvaged but still rare.
All of the contents from the new crates are either strangifiers, strange parts, or killstreak kits. Kits can be specialized or professional, albeit rarely.
New chemistry sets dropping, they have an expiration date and cannot be partially completed. They appear to be strangifiers for all strongbox cosmetics.
The backpack UI has changed to page numbers rather than left/right arrows, and when looking through numbered-page lists or dragging an item, the list wraps (so you can right-arrow from page 8/8 to page 1/8, for example)
Thief promos are craftable, and I'm happy to report that the compound bow drops, not just craft-only.
Below post contains patch notes.