Error while loading shared libraries: libgthread-2.0.so.0
Solution 1:
I'm not sure this warrants a separate question so I'm posting it here. In order to install IDA Pro on Ubuntu 14.04 64-bit, it requires a few more 32-bit dependencies:
sudo apt-get install libfontconfig1:i386 libXrender1:i386 libsm6:i386 libfreetype6:i386 libglib2.0-0:i386
Once you install those, IDA appears to start fine.