Here's the timeline from the Bob the Pleo calendar:
Pleo officially unveiled, 2/7/2006
PleoWorld.com launched, Pre-orders for original pleo began 6/21/2007
Bob the Pleo comic strips started, 10/2/2007
1st pleos shipped/arrive (First hatch), 12/5/2007 (Ugobe Pleo birthday)
Bob the pleo hatched, 12/8/2007
PleoWorld.com vanishes / Bob the pleo forums launched 12/12/2008
Ugobe files bankruptcy, 4/17/2009
Innvo Labs formed, 7/14/2009
Pleo 2009 version released, 10/10/2009 (Pleo 2009 birthday)
Pleo RB unveiled, 10/13/2010
Pleo RB ships worldwide, 12/17/2010 (Pleo RB birthday)
Pleo Merlin Edition released, 8/11/2011 (Merlin edition birthday)
Dates for the Pleo RB are a little hard to pin down as it was released at different times in different locations. It was first available in Hong Kong, and then in the Asian Pacific area before going world wide. The blue and pink versions were originally only available in the Asian market.