The most improvements that the platform's offer are In the internet have a lot of rumours, but.. seems that the follow are true):
1. On the fly editing lists. No need to change to datasheet view.
2. With Sharepoint 2010 you can Insert and Retrive Information throw Business Data Catalog (BDC)
3. Doesn't support IE 6.0, because SharePoint 2010 will be “targeting standards based browsers (XHTML 1.0 compliant) including Internet Explorer 7, Internet Explorer 8 and Firefox 3.x. running on Windows Operating Systems".
4. Improves the UI features, ajax controls, etc.
5. Enables the communication to other CMS.
Thanks!