First off, if software companies haven't caught on to virtualization yet, I would have to ask, "Why not?" It would certainly benefit software companies, [because there are] benefits from VMware and virtualization for [software] development itself. VMware has alliance programs for software ISVs that those ISVs can certainly take advantage of. VMware is certainly not pushing them away.
When I do run into a software company pushing back on support of their products running on VMware, the first thing I ask them to produce is a hardware compatibility list for their product, complete with make and model numbers. I've never yet received one of those because these software companies push back against VMware [not] because they know it won't work or there's a problem with it, but because they haven't tried it themselves [and] they aren't comfortable with it.
So it's important to really sit down and talk with your software vendors when they do start giving you some pushback, and certainly look to your partners or VMware to help with explaining to your software company exactly what virtualization is and how it can benefit them. It's a matter of simply managing the fact that there are companies out there that are not yet comfortable with virtualization. I think it's just a matter of educating those companies.