I have expirienced same problem,
i ran "update all" in appstore, after an hour i wanted to see if its done and ipad didnt turn it on. I tried hard reset several times but nothing happened.
I googled around and figure out that the solution should be restoring to default settings. I went in recovery mode, itunes successfully detected ipad, i hit restore and i get 1611 error.
Till then my ipad keeps restarting. I followed
http://support.apple.com/kb/TS1275 on 2 different OS (osx&win7) with no difference.
what should i do? did i brick my ipad?