Then there is the gray area in between. Lots of vendors are feverishly slapping "Cloud Ready" on top of their now dated SOA stickers (which were slapped on top of the Component Based, J2EE Compliant, Distributed and Web stickers). It's like the clearance items on the last day of a going out of business sale or your Ski Jacket on the last day of the season after an active year on the slopes.
Some software firms are simply tossing their packaged offerings onto a provider cloud and presto-change-o, check out their new As-A-Service capabilities! "Unlike [fill in competitors]
A wise man once said, "Ya know, a town with money is like a mule with a spinning wheel - He doesn't know how he got it and damned if he knows what to do with it." This prophet, of course, is none other than Lyle Lanley, selling the town of Springfield on the joy and profit of buying and operating their own monorail. And this parable is mentioned only partially in jest.
The Simpsons provide a lot of sage advice in their fractured fables. Some young writer named Conan O'Brien spun that particular cautionary monorail tale of the consequences of wanting to be like The Other Guy when he has something shiny and new.
The Simpson clan's Joy of Sect provides similar enlightenment on the dangers of simply following 'The Leader'. The 'Cloudists' and 'SAASians' of the world today remind me in some ways of Movementarians in this episode, managing to brainwash virtually an entire community with vague promises and subtle threats (well, not so subtle, perhaps).
Who needs the Bible or the Koran (or Dianetics) when you have the Simpsons?
I should be very clear that I think Cloud Computing and especially Infrastructure As A Service is much more a game changer than a lot of hot air. That's not even debatable: the game has already been changed by it for 1000s of companies who couldn't otherwise have afforded a web presence for their business (and in any case were most definitely priced out of handling their peaks and valleys of demand online). The idea that you don't have to buy or lease your own hardware and can scale up or down based on need (or on your available budget) can't be overstated. Well, it can be (and has been) overstated for fun and profit by the shills and shamwows I've been bemoaning, but it's a powerful thing nonetheless.
In the end, ya just gotta remember that not everything is meant to be cloud enabled or provided As-A-Service. I see what I thought were otherwise reasonable people trying to twist their square requirements into round fluffy white holes and star-shaped As-A-Service slots simply so they could have the industry analysts label them into the magical wavy quadrants with the most snap-crackle-pop, virtual-cloud-as-a-service being the snappiest right now.
And the cloud doesn't write your business applications for you. You still have to do that. They still probably have to abide by a set of business rules (which can include regulatory and security constraints that go beyond what at least many of the big cloud providers can offer today).
There are also technical as well as other constraints at play here. Bandwidth, distribution, data ownership/protection, legal worries. They all still apply. Lots of smart folks are working through most of these concerns and they are all in the end solvable if they haven't yet been. But they are solvable in the large, not necessarily solvable for you.
For instance, if you still need to talk to a system of yours that cannot be provisioned in the cloud, you'll probably need to at least ensure that the conversations are not lengthy or chatty, lest you surrender scalability in your pursuit of scalability (or marketability). If that's not possible due to the centralized nature of such a system, then you might have to hold off on your trip to the heavens (at least in this particular case).
Like anything, due diligence shouldn't be skipped in the mad rush to be relevant. Take a peak into each vendor's 'Forbidden Barn' before you eat what they're cooking.
Finally, check out others that have gone before you with a similar profile who might prove instructive. You'll want to see how the North Haverbrooks of the world are making out.