I'd be worried about using closed source software in my firewall, for example. With regard to our own development, it's very unlikely that we would open-source our major products. At a minimum, we would be in breach of NDAs if we did that. However, we are considering opening some of our libraries and components. In fact, we have already released an Open Source COM component, partly as an experiment and partly because I feel we need to give something back to the community.
Infrastructure is vital.
You can't build solid systems on a fragile foundation. In addition, interoperability is vital. This means infrastructure is almost a 'natural monopoly'. And nobody really wants to develop for multiple platforms, so the commercial world seems to tend towards a single-OS situation. If we are going to have one dominant OS, it should be Open Source.