The only difference between NN5 and NN5 Lite is that NN5 Lite doesn’t have upper rotator stops.
The NN5, release date expected mid 2008, will have upper arm 15 degree positive stops. These stops will be detachable "on the fly" meaning no tools or disassembly required to remove 15 degree stop feature.
Owners of NN5L will be allowed a trade-up for an estimated price of $50.
NN5L stand alone is currently selling for $349.95 while the NN5 with upper arm stops will retail for $50 more ($399.95). Package prices will include more components and sell for a bit more.