I wonder how the cost works.
At one time, NEXUS was cheaper than GE, and GE was 'free' if you already had NEXUS.
If that is still the same, I wonder if it makes sense to renew NEXUS first, then renew GE?
(edited to add):
Now I'm even more confused.
http://www.cbp.gov/xp/cgov/travel/tr.../ge_kiosks.xml
This 2/16/2012 link says NEXUS is good at GE kiosks, as long as you've gone to a GE center and done the fingerprints. ?? I don't see how that is going to work. I'm not sure if that means that renewing NEXUS first still gets GE for no additional cost.