The history tells it. Three solid patterns for MB/MBP updates since 10/2006.
Pattern #1: MBP got updated every 8 months. (10/2006, 06/2007, 02/2008, 10/2008, 06/2009) The next will be 02/2010!
Pattern #2: MB got updated every holiday season. (11/2006, 11/2007, 10/2008, 10/2009)
Pattern #3: Every MBP update came with MB update as well (or within a couple of weeks). (05/2007, 02/2008, 05/2009) The next MB update will be 02/2010 with MBP!
So I'm 99.99 percent sure Apple will update both MB and MBP this month unless, well, they don't.
Pattern #1: MBP got updated every 8 months. (10/2006, 06/2007, 02/2008, 10/2008, 06/2009) The next will be 02/2010!
Pattern #2: MB got updated every holiday season. (11/2006, 11/2007, 10/2008, 10/2009)
Pattern #3: Every MBP update came with MB update as well (or within a couple of weeks). (05/2007, 02/2008, 05/2009) The next MB update will be 02/2010 with MBP!
So I'm 99.99 percent sure Apple will update both MB and MBP this month unless, well, they don't.