I call it a mixed bag, the pros (100% EQM) equal the big bump-ups in mileage requirements for award travel/upgrades. Some of the increases in mileage are quite hefty for WBC:
a 25% increase to Europe (80 to 100K)
a 33% increase to Asia (90 to 120K)
a 50% increase from coach to WBC to Europe (20 to 30K)
a 20% increase from coach to WBC to Asia (25 to 30K)

I wouldn't expect any better benefits for elite members this year compared to the last, at least for international travel. Joining the Skyteam probably pushed NWA to mileage increases. So, I guess that improved access to the world now has a slightly higher price.