There are some public details about InfoPath 2010.
to summarize:
- Pre-built page layouts and section layouts.
- New Controls:
- Picture buttons.
- Hyperlink capabilities.
- Date and time picker.
- Person/Group pickers – Updated.
- Signature Line (Editor Only).
- New supported in browser controls:
- Bulleted, numbered, and plain lists.
- Multiple selection list boxes.
- Combo boxes.
- Choice group and sections.
- Filtering.
- Quick publish.
- Use InfoPath to create initiation and task forms for workflows.
- New InfoPath WebPart that supports connections.
- Use InfoPath to design BCS CRUD forms.
But the more exiting feature is definitely – The ability to create custom list forms for SharePoint lists using InfoPath. quote:
Using InfoPath, you can now extend and enhance the forms used for creating, editing and viewing items in a SharePoint list. In a browser, simply navigate to a SharePoint list, and on the SharePoint Ribbon under List Tools, choose the Customize Form option. This will automatically generate a form which looks very similar to the default out-of-the-box SharePoint list form.
Customize Form Command in SharePoint Ribbon:

You can then customize and enhance this form by modifying the layout, creating additional views or pages, and adding rules to validate your data, show or hide sections of the form or set a fields value (to name just a few of the options).
More Info at: http://blogs.msdn.com/infopath/archive/2009/07/15/what-s-new-in-infopath-2010.aspx