With the recent announcement of their amnesty program and the accelerated decline in sales (arguably caused by consumer animosity), I am going to go out on a limb and say that we will see a rapid decline in the number of subpoenas issued.
Below are a couple links. Disclaimer: These are links to my site, but my site IS a digital music / media news site so I feel the plug is warranted.
Sharing / sales numbers:
http://tfproject.org/tfp/showthread....threadid=25584
Amnesty program:
http://tfproject.org/tfp/showthread....threadid=25684
(Edit: pointed to relevant TFP links where possible)