Actually I have written an article about some classes and methods you can use to ease your life when implementing things for SharePoint 2007. The article contains some examples of

• Microsoft.SharePoint
• Microsoft.SharePoint.WebControls
• Microsoft.SharePoint.Publishing
• Microsoft.SharePoint.Publishing.WebControls

This article will be published later because today I have read at the Microsoft SharePoint Team Blog and the Office Sustained Engineering blog that they have announced the release of Service Pack 2 for Microsoft Office SharePoint Server 2007 (MOSS 2007) and Windows SharePoint Services 3.0 (WSS 3.0) between February and April 2009. The following topics are included in Service Pack 2 (Source Microsoft SharePoint Team Blog):

• Improved Read-only Content Databases
  Whenever a content database is marked read-only, all of the site collections in that database are automatically marked as read-only. 
• ECM Performance and Manageability Improvements
  Improved performance and manageability in variations, including STSADM commands for repairing links between source and target pages.
• Improved Index Rebuild Timer Jobs
  SharePoint content databases running in SQL Server 2005 will undergo an automatic index rebuild, which helps stop defragmentation, and stop the database from degrading in performance.
• Upgrade Checker
  This will scan your SharePoint farm in advance of applying SP2 and will provide feedback on the environments readiness to upgrade.

Details about the topics will be explained in further blog posts by the different product and team blogs. In the meantime there are cumulative updates for SharePoint 2007: Announcing August Cumulative Update for Office SharePoint Server 2007 and Windows SharePoint Services 3.0