Jan Tielens has released Version 1.1 of SmartPart, which is a SharePoint WebPart that allows you to host ASP.NET User Controls inside itself.
This approach simplifies SharePoint Development as much as possible.
Version 1.1 Features:
- custom toolpart support
- access to the underlying web part
- "hidden" custom properties
- various minor improvements
More details on SmartPart 1.1