The FAQs say:
. . . US Airways will also continue partnerships with some partner airlines, so you'll continue to earn and redeem miles when traveling on Aegan, Air China, Air New Zealand, Shenzhen Airlines, Singapore Airlines, South African Airways, TAM, TAP and Turkish Airways.
What they don't say is whether flights booked on these airlines after 3/31 will still count as elite-qualifying miles (or just as regular miles). Has anyone seen an answer on this?