Any businessperson who's going to bet the company on a technology decision wants to minimize risk. Sure, you want to get a bargain... but you also want to ensure that the company from whom you're purchasing the software will be around, and that the support will be there when you need it. No matter what the distribution method is.
What are the leading indicators that an open source company is safe for enterprise adoption? Who can IT trust and why?
How does an open source project's revenue/business model affect an enterprise's willingness to adopt it? Perhaps we should distinguish, here, between how it does affect the decision-maker and how it should do so.