"Colgan will purchase and take delivery of 15 additional Q400 aircraft to be operated under the capacity purchase agreement (the "CPA") between Continental Airlines and Colgan. The aircraft will be delivered between August 2010 and April 2011."
"PNCL also obtained 15 optional delivery slots exclusively for Continental for Q400 aircraft delivering in 2013, subject to PNCL obtaining commercially reasonable financing for the option aircraft. PNCL still retains 15 options for Q400 aircraft delivering in 2011 that it may market to other major U.S. airlines."
From the PNCL website.
There are only 15 more coming, the rest are only options and no statements have been released about exercising the options.