Visualize this. You have a IaaS provider, then a SaaS provider (possibly multiple), identity provider and so on. And each has a disparate access policy. The rumblings should be clear by now. A classic case of cocktail of systems. Of course you dont want to tie it back to your own systems for access purpose. It defeats the Cloud vision. moreso, it becomes a daily routine to coordinate with so many vendors.
So whats clearly up in the air is a requirement that all Cloud providers work towards a single sign-on option. Implementation is not in scope of this blog post. I do see many ways of reaching only if the spadework starts now.
As with my other blog posts, I do see a big market opportunity for someone to solve this problem.
And if you do solve it, pls inform me so I could throw away those scraps of paper with codewords to remember my URLs and passwords.