Oracle Database 10g Release 2 for Windows is now available for download from OTN, relatively quickly on the heels of Linux x86. All major versions are now available.
Also, .NET developers will be interested in the new "Mastering .NET Application Development with Oracle" series, which also debuted today. (Part 1 is from Oracle ACE Mark Williams--author of Pro .NET Oracle Programming--on using ODP.NET and ref cursors to optimize result set retrieval from the database.) This series will be particularly interesting as future installments will zero in on securing .NET apps on the Oracle Database, as well as techniques for building and deploying .NET stored procedures via Release 2's new CLR extensions.
As always, the .NET Developer Center is full of other good stuff for developers of that ilk as well.