The Exchange Developer blog has a post updating the future vision of Exchange development.  If you remember, there was a post on the Exchange Team blog back in September 2005 that gave us the first glimpse of this vision leading up to Exchange 2007.  The vision has come into focus some more but the overall direction hasn't changed in the two and a half years since the first Exchange 12 roadmap post.

Here are the important notes from the roadmap…

1. Exchange Web Services are the API of choice in Exchange 2007 and beyond for mailbox and public folder access.
2. The web store APIs (WebDAV, CDOEX, and Store Events) which are de-emphasized in Exchange 2007 will be going away in the next release.
3. The MAPI and CDO 1.21 download will be aligned with the lifecycle of Exchange 2003, meaning they will be moving to extended support in the near future.
4. Since at this point store event sinks will be gone in the next version of Exchange, synchronous event processing with OnSyncSave and OnSyncDelete will not be possible.

We’d like to hear from you about the last point…

I am working with the product team to discuss any scenarios where EWS notifications and Transport Agents might not be sufficient to replace synchronous store event processing in a custom solution.  The Exchange development team and my Exchange support team are aware of the potential challenges arising from changing the development interfaces available.  Between Exchange Web Services notifications and Transport Agents we feel that we can fill a lot of the gaps left by removing synchronous store event processing but we want to hear from you.  Are there scenarios that you currently require synchronous event processing for right now?  Please email me or leave a comment describing your scenario. Getting your feedback will help us prepare documentation, workarounds, or solutions that can mitigate the challenges presented by this change.