As Andreas has mentioned, the next webinar will be on this topic. If you cna wait until then, you should be able to get a lot more information and even talk with the developers if you have any questions.
If you can't wait, check out the UC2009 discoveries webinar, where Ray discussed the outline of the Data Services. Whilst not a concrete definition of the new product, it will give you a good understanding of where it is going and allow you to steer your design down a "probable" path. It may mean that, when PI Data Services is released, you will only need to change the method signature instead of logic etc.