In case you didn’t know, Microsoft has released ASP.NET AJAX and official support for it in SharePoint 2007 will be coming when Service Pack 1 comes out for SharePoint 2007.   

Here are some common scenarios in SharePoint you should be able to achieve with Microsoft ASP.NET AJAX 1.0:

1. Building a more powerful, re-usable JavaScript libraries you can use in your web controls and parts
2. Enabling your web services to render via JSON, resulting in easier usage in JavaScript/Ajax Applications
3. Building a web part that takes advantage of Extender technology to provide richer interaction styles, such as autocomplete on a textbox.
4. Using an UpdatePanel in your web part or control for more fluid, no postback interaction. (this will require some workarounds, however.)

There’s a great post Integrating ASP.NET AJAX with SharePoint by Mike Ammerlaan, here’s a content summary:

• Microsoft ASP.NET AJAX 1.0: A Background
• Microsoft ASP.NET AJAX 1.0 and SharePoint
• Adding Microsoft ASP.NET AJAX Technology to SharePoint Pages
• Installing ASP.NET AJAX on servers in your farm
• Extending SharePoint web.config files with Microsoft ASP.NET AJAX 1.0
• Adding a ScriptManager into a SharePoint MasterPage
• Using UpdatePanels within SharePoint
• Output Caching and ASP.NET AJAX
• Conclusion
  Microsoft ASP.NET AJAX 1.0 provides great building blocks for building rich Ajax-enabled applications.  Combined with the power of the SharePoint platform, and knowing some of the integration limitations, you can build powerful Web2.0 applications that bring together the best of both of these technologies.

I definitely look forward to more content and examples of what we can do with ASP.NET AJAX and SharePoint.   If you would like to see actual videos on how to develop and code with ASP.NET AJAX then check out the first link below:

• Free ASP.NET AJAX 1.0 “How Do I?” Videos (Updated for Final Release)

• Integrating ASP.NET AJAX with SharePoint

• ASP.NET AJAX and SharePoint