Here's the long story short:
Microsoft may have supposedly rolled out a broken update that broke support for Exchange\ ActiveSync \ Corporate Sync (depending on your device)
So here's my question.
1: Do you have a Hotmail\Live Mail account?
if yes, go to question 2, if no, skip Poll
2: Do you have a smart device that supports Exchange? (tablet, phone, handheld)
if yes, go to question 3, if no, skip Poll
3: Does it work?
if yes, answer poll, reply with smart device specs (OS, Manufacturer and model, etc) and when it stopped working\got fixed
if no, ignore\answer poll with "Does not apply"

Doing this to see how widely the issue is, hopefully it will help be able to identify if a fix for this issue has rolled out\how many people here are affected. You should be able to provide better responses than most of the people on Microsoft's "support" site.

Thanks

Sync with Exchange servers works fine here.
OS : Windows Mobile 6.5 (build 21867.5.0.68)
Manufacturer : LG Electronics
Model : GM750 "Layla" (Vodafone branded version of GM730)
Sync status : never failed

Don't know what happened but everything's fine here.

Are these the Hotmail exchange servers? I can sync with gmail exchange or other exchange servers, but using Microsoft's Hotmail Exchange service (m.hotmail.com) is broken for me, and many others.

I'm certain these are because, after Microsoft pulled the plug on MyPhone (and other WinMo services), all my data was migrated to my live account and I had to follow their instructions on syncing with the mail Exchange servers to get things running again.

EDIT : checked again the server address. Yes, its m.hotmail.com

It started breaking for me just today, from my tablet. Could not connect to server.

Not sure why, this is very inconvenient.