Well, depends upon what you mean by "next".
BECAUSE, the "next" one starts this Sunday, 01/31/10 with the test on Saturday, 02/06/10.
Then, there is one in Spokane in June. And another in Seattle in Aug I believe. It is either July or Aug, short memory, I just looked at it.
You can click on 'AWS Website' on top here, then on 'certifications', go to 'fees and scheduling', then to the testing you are interested in.
Have a Great Day, Brent