Make no mistake - cloud computing is not just the trend du jour - it's a seismic shift in the IT landscape - with big implications for the IT departments of ALL organizations - from the local veterinarian's office to the largest multinationals.
For an IT department, it's very easy to look upon cloud computing as an encroachment onto your turf by a hostile force with bad intentions. Vendors come and make extravagant promises about availability and efficiency that few in house shops can meet, but that users believe. It's clear, to grow their businesses, cloud computing vendors are going to have to take "computational cycles share" from somewhere - namely - you and your department.
Fighting - or arguing - against a tidal wave is fruitless. The best strategy is to run for higher ground with the most valuable possessions you can protect. And, even though the old IBM and Digital Equipment terminal salesmen are laughing from their retirement homes, there is merit in the cloud computing (read - distributed) model. Rather than fighting the integration of cloud computing into your company's business models, you might consider how to best incorporate, support and own it as a resource with IT as its gatekeeper.
Truth be told, some applications best live in the cloud, where economies of scale can be achieved, best practices integrated into applications, and software maintenance is easier. Of course. with the applications go the hardware, and precious budget dollars and turf.
One suggestion is to sit with senior management and identify the core competencies of the organization, mission critical applications and data, and other services best left in house, and cede some territory, while gaining management over the new company "resources."
A major, but unspoken, attraction of cloud computing, is that they treat the rest of your company as a customer, something your users might not say about you and your department. And that's something you can change, by altering the culture within your organization. Don't make your users feel like they're at the DMV. Cloud computing, while it enjoys real efficiencies of scale, is not magic, even if the vendors' salespeople promise to pull rabbits out of their hats.
Pick your battlegrounds, articulate your case regarding the best interests of the enterprise, and treat your users as customers - and cloud computing, like the internet, will be another asset under IT management.