Your guess is as good as mine.
A few months ago the sky was the limit for as far as new bases were concerned, but recently things seem to have cooled down significantly. Low yield routes are given the chop (AMS and ZRH) and old and expensive (high lease cost) -300´s are returned as STN will go Airbus in the first half of 2005.
My guess will be that all -700 bases will stay -700, while most current -300 bases will change to the Airbus with some moderate expansion (read: new Airbus bases) in Europe over the next 2 years.
LTNman, as far as I´m aware all 737´s have been delivered and as a direct result Boeing training has slowed down quite a lot. The main focus seems to be on Airbus now.