I get the same behaviour on Linux ubuntu 13.04.
I've been able to stop/restart the process and make some progress until :
Gathering assets list from http://resources.download.minecraft.net
Downloading 1086 assets
sounds/fireworks/largeBlast1.ogg Modified, removing
I can't get past this.
I tried: iptables -F = to make sure there were no firewall issues. There are no issues. I don't use any iptables rules on this box anyway...
I'd very much like to get this working. Would folks recommend I google around and try to find the gradle install mechanism?