Here's a list of IBM-published Redbooks relating to .NET
WebSphere and .Net Interoperability Using Web Services. 366 pages. June 2005. DB2 UDB V8.2 on the Windows Environment . 356 pages. October 2004.Integrating DB2 Universal Database for iSeries with Microsoft ADO .NET . 282 pages. April 2005.Lotus Domino and .NET Coexistence . ??? pages. April 2004.Websphere and .NET Coexistence . 606 pages. May 2004.WebSphere MQ Solutions in a Microsoft .NET Environment . 360 pages. January 2004.
I haven't looked at any of these in detail yet.
In addition, IBM has published a bunch of other papers and articles on using .NET with pieces of IBM infrastructure:
IBM DB2 Data Access Application Blocks for .NET April 2005Creating and Linking LOBs with .Net and DB2 UDB April 2003Developing .NET Applications with IBM Rational XDE using C# May 2004Websphere and .NET working together August 2003ADO.NET and Cloudscape October 2004
In addition, don't forget the various software IBM delivers:
IBM also offers services around .NET: implementation and training, too. Maybe IBM is starting to come around on this .NET phenomenon? ;)