What's new in SharePoint 2010 Sites

1. Role/Rule based Audience Targeting – added rules-based audiences, WSS groups and distribution list membership.
2. Sites are collection of pages - SharePoint 2010 sites became more page-focused rather than a collection a lists. Sites still contain the same list and libraries as previous versions of SharePoint, but the site is now a collection of pages.
3. Pages are optimized for Reading – all WCM pages are optimized for the reading, rather than for the writing, thus performance is increased significantly
4. Status updates and activity feeds of My Sites – SharePoint 2010 changes of My Site enhanced dramatically to be the social networking hub. One of such changes is ability to update your status, similar to Facebook. See the following screenshot
5. Social tagging - assignment of descriptor words or categories to that content.  There are two types of tagging, social tagging and expertise tagging.  Social tagging refers to content and adds metadata to content to describe what it is, what it contains, or what it does.  Expertise tagging is related to a person and describes the person, such as what they do, which projects they work on or what skills they have.  Where social tagging of content allows users to organically flex and grow a portal’s information architecture over time, expertise tagging helps build relationships and connections to other people in the organization.
6. Team blogs which allows multiple people to publish blog posts together
7. New Lists - Assets Library (list to share and manage rich media assets such as image, audio and video files) , External List (list whose data source is an Enterprise Entity)
8. Site templates are deprecated in SP2010. But, "Save Site as Template" will create a solution package with a .wsp file name extension
9. Improved performance and management of large lists.  List item limitation has been removed – 1 million items for 3 secs. Windows SharePoint Services "14" and Microsoft SharePoint Server 2010 apply a default query threshold of 5,000 items. Any custom code that relies on query result sets that can exceed this maximum will not behave as expected. Queries on lists consisting of more than 5,000 items that include non-indexed fields in their query conditions will also fail, because those queries must scan all rows in a list. You can increase this limit or enable the object model to override it on the Central Administration site (under Application Management, click Manage Web Applications, click General Settings, and then click Resource Throttling
10. Lists support external data, can return results as DataTable; support calculated field rule validation and no more even’t receivers