Jason Langridge recently blogged about some differences between iPhone 3G and Windows Mobile in regards to Exchange ActiveSync.  Some interesting differences.  Available also is the Enterprise Deployment Guide directly from Apple.

Both are enlightening reads and about differences in the implementations – check them out.  <spoiler> Windows Mobile and iPhone do not have parity with regards to Exchange ActiveSync </spoiler>

Updated 2007/07/06:  Updated link to iPhone manual.

“Note: Exchange email accounts must be configured for IMAP in order to work with
iPhone.”    -iPhone Manual, page 44.

Prediction #783:  Help desk folks nation wide will get flooded with queries on Monday morning checking if Exchange is configured for IMAP.  Meh.
In most of the organizations I know, the answer would be (in the kind words of a British friend):  “Not bloody likely.”