From your description, no.
Agree with Bob. PDF retains layout and proportions with no reflow. You can only scale larger or smaller.
EPUB is designed for reflow.
There is a reflowable form of PDF but the limit is your target platform. There is no "default PDF Viewer" for the iPad -- Apple's own, inside iBooks, is as limited (or more) as their poorly desktop Preview implementation. There are lots of other PDF viewers, all with their own unique set of own limitations -- even Adobe's first tentative version doesn't do very good on the 'Pad. Smaller mobile devices even have *less* brain capacity, and I don't think you can expect anything better on short notice.
On top of that, InDesign does not allow for designing a "reflowable" document. There is a pretty good demo movie of a proof-of-concept technique, but that's all it is -- a *possible* line of development for a future ID. I can't tell at this time but I'd be quite surprised if this made it into CS6 already.
Still -- even if InDesign can reflow layout, text and images and all, for you, you would still be looking at producing a dedicated document per current screen reader size. If you want to target lots of different devices, you might want to even look slightly *lower* than an ePub: a plain HTML document *with* images can be viewed at about every phone, at any size the user finds convenient.