One of the major difficulty with InfoPath 2007 is you cannot set WebServices URL Dynamically.
I found some solution , One suggestion here to change Change on form load but problem here is
you cannot directly publish because it contain code behind.
Another option using Data Connection file again it increase post deployment work also
if the Infopath form has lots of method inside then change every where.
Again if you have multiple form then its huge post deployment work and need to check each
and every functionality.
From MSDN find and replace manifest.xsf file with appropriate url and publish it, this way no
post deployment work.