I've been playing with ObjectSpaces (OS) lately. I like the idea and the implementation is pretty good. The main limitations I see are:

• For the foreseeable future, it will only talk to MSSQL (and it's various flavors). If they're writing an Object Persistence Framework (OPF), shouldn't someone have mentioned that they should probably abstract out the DB-specific stuff? I understand this is 1.0, but please, that is so limiting that it almost makes OS unusable. Do I really want to have DB lock-in to MSSQL? I don't think so.
• It is tied to Whidbey. With the delay shipping Whidbey, this means that we won't see a production-capable version of ObjectSpaces until Q1 of 2005! That is a long time to wait to get OPF. Microsoft should find a way to unbundle certain pieces of the PDC preview - such as ASP.NET 2.0 and OS - and deliver them on a schedule that is independent of an IDE release.

At any rate, here is some good material to help get up to speed on OS:

• PDC presentation
• Matt Warren's Blog
• Gopalan Suresh Raj
• Getting Started with ObjectSpaces
• Overview of the ObjectSpaces Architecture

I plan on writing some articles detailing my experiences (good and bad!) with OS, discuss alternative OPFs, including ECO (available in C#Builder and Delphi 8), and flesh out some best practices when using this kind of technology.