It looks like some kind of service issue.
looks like the issue is being discussed everywhere
Google Play: APK upload never starts or gets stuck at “processing” : androiddev
I just made a successful upload. Hope its also fixed for others!
me too! after trying for 7 hours APK and screenshots are in
So did I (in the US)
I used VPN thou Canada if that helps, UK and USA did not work at the time , Canada was instant upload
It still does not work for me…
There is a notification in the developer console regarding this issue. It says that Google’s team is working hard on fixing this issue asap)) So at least they’re aware of this.
Successfully updated!
Yep, working now!
Just got up here in India. While I was sleeping, they fixed it 
Seems like their servers are super backed up, the app I published earlier still isn’t live after 8 hours…
For me it also did not work. I will try again later,hope than it will be work.
this explains it!
Hacker crashes Google Play – twice - Mar. 17, 2014
Everything seems to be back to normality now (check the announcement in the Developer console)
“But developers are furious.” - overstatement of the year I suppose 
Lol annoyed maybe, not furious…
hmm all my apps are not posting as well and sometimes when i go back to check on them later they are suspended with no email as to why. Im assuming this bug is coming to pass and we can get back to posting. Highly annoying. Now ive got a bunch of accounts with 1 suspension in them. Cant seem to keep an app up as long either 