In case you haven't seen this yet, the CTP release has been announced at http://blogs.msdn.com/astoriateam/archive/2009/08/31/ado-net-data-services-v1-5-ctp2-now-available-for-download.aspx.
Following the philosophy that folks like tables, here you go.
|Feature||Available in CTP1?||New in CTP2|
|Data Binding||Yes||API cleanup for types|
|Row Count||Yes||Bug fixes|
|Feed Customization||Yes||Renamed attributes and more flexibility|
|Server Driven Paging||Yes||Client library support|
|Enhanced BLOB support||Yes||Client library support|
|New Provider Interface||Yes||API refactoring|
You probably want to keep checking the blog, as there are some posts coming that will dive deeper into some of the new features.