Is the new Apps of Office/Outlook the extension/add-in mechanism we have been looking for? (i.e. a "real" write once, run anywhere...?)

Apps for Office and SharePoint Blog - A closer look at apps for Outlook

"Rolando has already given an overview of how apps for Office work, so today I'm going to drill into how apps for Office run within Outlook. Apps for Outlook, or "mail apps" as they are sometimes called in our developer documentation, are apps for Office that are optimized for running in Outlook against mail and calendaring information. We have built far too much for me to cover everything in detail in one post, so today I will give you an overview of apps for Outlook using some of the exciting apps that our partners built for the Office 2013 Preview, to demonstrate the power of this platform. But first, let me introduce myself.

My name is Jason Henderson and I've been working on Exchange for the last 10 years. I started on the Outlook Web Access team, and then led Exchange Programmability on the Exchange Web Services team, and am now back to the Outlook Web App team where I've been lucky enough to lead a team whose charter combines my two passions—building great end-user experiences and enabling third-party developers to easily extend and enhance the rich experiences we build in Exchange and Outlook with their own unique value.

Let's get started!

Write once, install once, run on desktop, tablet, and phone

The apps for Office platform gives Outlook developers an incredibly powerful tool to help make end users productive across multiple platforms. Developers no longer have to learn multiple technologies to target Outlook on different platforms. Now, a single HTML5 app for Outlook can run in the Outlook rich client and Outlook Web App on Mac, PC, and iOS using the same code.

It has always been very difficult, if not impossible, for developers to extend the mail clients on most mobile phones and tablets, yet there are many incredibly compelling scenarios for integrating third-party information with mobile mail applications. With apps for Outlook support in the Outlook Web App experience on iOS, we are now making it very simple to create an app that is available to a mobile worker in the context of their work email. Simply create an app for Outlook, modify your user experience to be touch-friendly, and publish the app just like you would for Outlook or Outlook Web App, making sure to specify an entry point for the phone form factor in the manifest. Your app will now show up when your users browse to the Outlook Web App experience on the phone, simple as that.

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This looks so cool and has so much promise that I 'm concerned. Is this too good to be true? Man, I hope not, because this could be one of the killer/must have features in Office 2013, a truly modern extension solution...