SharePoint Developer: What new you can do in SharePoint 2010

1. System requirements for server or developer machine is 64-bit and minimum Dot Net Framework 3.5.
2. SSP is not longer existing as it used to be there is now Service Applications.
3. Workflow is now not limited to items or lists.
4. Development can be done in a client OS (recommended : Windows 7)
5. Web Parts can be placed without web part zones.
6. UI Shifts (Ribbons, In Place Editing).
7. Claims Based authentication is added.
8. Sandbox Solutions (isolation and resource limitations (memory, SQL, CPU) that allows administrators to let others safely add and consume custom solutions without impacting overall farm performance and stability)
9. Developer Dashboard (can be enabled on a page to view more information that helps the developer in performance tuning and troubleshooting issues related to page rendering)

New Things in SharePoint Development Platform :

1. Pages and user interface (sliver light, XSLT views).
2. Server API’s (LINQ).
3. Connected Client API’s (REST, Client OM).
4. Application Model (Sites) – External lists.
5. Power Shell

Cheers!!!