Hmmm... RSS/ATOM feeds are down as well.
The mobile site seems down for me from a regular browser... not sure if the app goes through normal channels though.
Ether way, whether app works or not, I'm doubtful anyone can upload, as the feed system is integral to that, generally if it is down, no on can upload.
Fortunately, I checked everything around 3:00am, and downloaded a few items... so I'm fine for the day.