I know I've posted on this before, but I got an email today asking, "Do you know anything about a new version of the NIV?"
Here's the state of my answer. The NIV 2011 is two things:
1. an admission of political/economic defeat in relation to the TNIV
2. an updating of the NIV
So is it better than the NIV? Yes. If you are happy with the NIV, go ahead and upgrade with the NIV2011. It is better.
Is it the best translation out there as a translation? No, not in any category. The NLT, CEV, and in some places CEB are better dynamic translations. The ESV, and in many places CEB and NRSV, are better formal translations, in my opinion.
Right now I'm using the NRSV and CEB in my writing.