Check it out — the InfoPath 2003 Toolkit for VS.NET was released a few days ago. My biggest gripe about InfoPath is that it relies on VBScript/JavaScript and ADO for its customization (e.g. anything outside the norm you want it to do). Well, according to the download page, the new toolkit:
provides integration features and documentation that enable you to use Visual Studio.NET to create, debug, and build InfoPath projects that use Visual C# or Visual Basic.NET managed code.
Nice! However, it also requires InfoPath 2003 Service Pack 1 or later, which you can get here. Apparently it’s a preview of some of the fixes that will be in the Officie 2003 Service Pack 1. I’ll definitely be playing with these soon – InfoPath rules for user experience when it comes to data entry (one person, lots of data) or data collection (many people, some standard data) scenarios.