Notch twitted that armor is still broken. Th emergency patch yesterday broke it. So from his twitter it may be a day or two till armor works again.
Other good info.
You can knock the fire balls from Ghast away with any equipped item.
Stone Picks will mine the blocks in the Nether.
Right now iron is very easy to find in new worlds or new chunks in an existing world and Notch considers it a bug.
You need much much more light at layers 1 to 16 to prevent mob spawning now. Right now my experiments resulted in 1 torch every fourth block distance being needed on level 11/12. That is a lot of light.
The update this morning 31 October fixed the lost inventory on death bug.
The 0.00 MB save files that people are seeing after going to the Nether are playable and not reason to panic. But backing up your world is still smart.
For those players that have not done it. Build a fortress around your gate in the nether and light it well. It makes the entry into the Nether so much safer.