What are some reasons your company hasn't invested in cloud computing?

Cloud computing is a new computing paradigm that promises to provide significant enhancements to IT capabilities, operations, and benefits, at considerably reduced costs. Once implemented, Cloud computing will differ drastically from today’s computing model. The primary and overriding reason for moving to the cloud, however, is financial. The financial benefits can be derived from increased revenues due to faster time-to-market for more relevant business offerings and/or reduced capital and operational costs. In either case the impact of moving to the Cloud will be enormous.
By most accounts, the transition to the Cloud does incur some risk, the greatest of which is the effort to migrate to this new paradigm and NOT achieve the desired result. The IT industry is bullish on The Cloud and is investing heavily in its efforts to prepare the Cloud infrastructure for both public and private use. The end-users however, such as ourselves, are looking to quantify the benefits before major investments and transitions are embarked upon.
The primary reason that we have not yet invested in Cloud technology is our need to quantify the risks and the costs. Yes, the Cloud is compelling, but we can't project how much we will save if we are't absolutely clear on how much we're spending and how those costs are allocated and recovered. We are therefore advocating an "Insfrastructure Audit" internally to understand our TCO baseline costs, cash flows, key financial metrics and ratios including Return on Assets.
Armed with this information, we'll be ready for a sound decision.