No prices have been announced, so it will be interesting to see what they come up with. Anyone with their own licenses can still use them. Anyone who is already running Oracle on Amazon would find it easy (and legal) to throw up another one for testing (maybe Real Application Testing, if you've got the money) or perhaps year-end reporting.
It would also be handy for demos and development outside the scope of the OTN licenses.With the facility to push your RMAN backups to the S3 cloud, you may even have scope for using Amazon as a DR.
Of course if you're in that group who are chucking terabytes of data around on a daily basis, then your hardware is near and dear to your heart and all this cloud stuff is a load of vapour. And then there's whatever restrictions your application, industry or country has on storing data as bits and bytes floating rounds the US.
If nothing else, the hourly rates will be interesting to factor in to any future negotiations about licensing for those database servers you don't need running 24x7.
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