Since my original posting I found a posting by Pelican.
http://www.pelicanparts.com/techarticles/Boxster_Tech/14-ENGINE-Intermediate_Shaft_Bearing/14-ENGINE-Intermediate_Shaft_Bearing.htm
Below are their findings.
The engine number of my 2001 Boxster S with a 3/2001 build date is M96 21/ 671 09227. According to a Pelican Technical Article, this engine should have a double row IMS baring.
The class action lawsuit states that single row bearings have an 8% failure rate while the double row has a 1% failure rate.
Engine Number Model Bearing Type
Up to engine # M 651 12851 Boxster 2.7L M96.22 Double Row Bearing
Up to engine # M 671 11237 Boxster S 3.2L M96.21 Double Row Bearing
Up to engine # M 661 14164 Carrera 996 3.4L Double Row Bearing
From engine # M 651 12852 Boxster 2.7L M96.22 Single Row Bearing
From engine # M 651 11238 Boxster S 3.2L M96.21 Single Row Bearing
From engine # M 661 14165 Carrera 996 3.4L Single Row Bearing
All 2005 Boxster 987 (maybe some 2006 models) Single Row Bearing
All 2005 Carrera 997 (maybe some 2006 models) Single Row Bearing
Maybe some 2006 Cayman models Single Row Bearing