The latest statistics on Ex Parte Reexamination (through December 2007) have been released by the PTO. As expected, the number of reexamination requests continue to climb:
2002 - 272 filingsThe success rate for requestors has not changed, and continues to favor requestors. Overall, all claims are confirmed in 26% of reexams, claims are changed in 64% of reexams, and 10% of reexams result in all claims being cancelled.
2003 - 392 filings
2004 - 441 filings
2005 - 524 filings
2006 - 511 filings
2007 - 643 filings
2008 - 165 filings
Average pendency of an ex parte reexamination is 2 years, and median pendency is just over a year-and-a-half (18.6 months).
Read/download PTO Ex Parte Reexamination statistics here (link)