Integrating BIS and OWA (2007) is dependent on a few things. The RIM support site has plenty of info on this. If Verizon is using BIS 2.4 and your company doesn't employ any security other than https, you should be ok.
I got my Pearl in April and we were on Exchange 2007 and could not integrate. All of a sudden in November/December it worked. BlackBerry Search Results
Your other alternative is to forward your email to a secondary account (GMail, Yahoo, or your "email@example.com").