The licensing pain is real, for sure, but OpenSSL is really all kinds of bad news. They, or whomever packages them, have absolutely no clue when it comes to shared library support/backward compatibility. What a nightmare.
NSS has one other very significant advantage over GnuTLS and OpenSSL not mentioned in this article: NSS has been blessed as the standard SSL library for LSB. So it will be available on all LSB-compliant installations.