From DP's own mouth during Town Halls and Crew News,
B-737 will probably stay. As each 737 lease comes up for renewal(about 10 in 2007)a decision will have to be made. DP said if he were a betting man he would bet they would stay.Money has already been allocated to fix long term(lap joints)problems on the 737. Of course this is all subject to change if another 9/11 event comes along,etc,etc,etc.The 190's give him the needed flexibility/leverage to negotiate 737 leases in his favor. Total aircraft count excludes 190's per TA. His hands are tied after Sept 06 to predetermined A/C amount which would not allow parking all 737 fleet. All this information(exceptTA) is available to everyone on the Hub. And no, I will not go back into the Hub to verify or give references for the naysayers,you will have to do a little work on your own.
If you just use a little common sense you would have to realize parking the entire 737 fleet is crazy!