Today I planned to publish a comprehensive post on our results and plans in my blog (it will appear in few hours), but you're going ahead of me ;) So:

• Lazy-loading in v4.0 is implemented much better. Moreover, there is much better prefetching (so ugly things like fill descriptors from v3.9 are gone).

• Caching: there are significant changes here as well. First of all, Session-level caching is more flexible now. You can choose among weak / strong caches there, set cache size & other properties, use chained caches, etc. There is no global cache yet, but in will appear on the next iteration. New global cache will also be much more efficient: there are no version check on reads from cache. Better description will go further.

• Versioning (or versionizing) from v3.9 will never appear in v4.0 - mainly, because this is very specific feature; moreover, this approach won't suit for large databases. But some day there will be undo support.

• Transactions: currently DO4 supports only outermost transactions. Nested transactions will appear on the next iteration.

• WCF: our general solution there will be O2O mapping (see the link below). Again, that's for the next iteration. If you're developing for WPF, likely, the simplest way is to use DisconnectedState there (will be shown on the next week - currently we have a version of our WPF sample already adopted to it).

• ADO.NET Data Services are already supported. There is a sandbox project showing this (+ Silverlight client) right in the distributive.

A list of features that will appear on the next iteration (~= December):

• Nested transactions

• Global cache

• Localization: http://code.google.com/p/dataobjectsdot ... tail?id=90

• Security: http://code.google.com/p/dataobjectsdot ... ail?id=253

• O2O mapping: http://blog.alexyakunin.com/2009/09/obj ... oming.html

We're starting it on the next week, so today I'll write more detailed list of what we're going to add. Moreover, this means v4.1 is turning from RC to release on the next week.

After getting this done, we'll be missing the following features from v3.9:

• Full text indexing and search. We have big plans there in v4.0, so when the time will come, you'll get really good API here. For now you can use e.g. this solution: viewtopic.php?f=29&t=5657&start=0

• Partitioning. We'll need this in ~ 3 months for MEScontrol, so this is in TODO list as well.