Update: SharePoint 2010 documentation
Since posting my last blog post - SharePoint 2010 documentation now available, I came across some more content available on Microsoft Download Center. Given below are the new resources I found:
SharePoint 2010: Developer Platform White Paper - An Introduction for ASP.NET Solution Architects by David Chapell. This white paper provides an overview of the SharePoint 2010 Developer Platform for ASP.NET developers
SharePoint 2010: Developer and IT Professional Learning Plan - This document provides information to help developers and IT professionals learn Microsoft SharePoint 2010
SharePoint 2010: Getting Started with Development on SharePoint 2010 Hands-on Labs in C# and Visual Basic - Use these 10 hands-on lab manuals for SharePoint 2010 to get started learning SharePoint 2010 development
SharePoint 2010: SharePoint Developer Platform Wall Poster - The SharePoint 2010 Developer Platform wall poster (PDF format) shows a view of the SharePoint 2010 developer tools, community ecosystem, execution environment, SharePoint Server 2010 workloads, and target application types. The poster is intended to be printed at 24 inches x 36 inches (61 centimeters x 91 centimeters).
Topologies for SharePoint Server 2010 - Describes common ways to build and scale farm topologies, including planning which servers to start services on
Hosting Environments for SharePoint 2010 Products - Summarizes the support for hosting environments and illustrates common hosting architectures
Microsoft Business Connectivity Services Model - Microsoft Business Connectivity Services enable users to interact with external data by using SharePoint lists and Microsoft Office 2010
Search Technologies for SharePoint 2010 Products - Compares and contrasts search technologies in SharePoint 2010 Products
Search Environment Planning for Microsoft SharePoint Server 2010 - This model describes primary architecture design decisions for search environments.
Search Architectures for Microsoft SharePoint Server 2010 - This model describes the physical and logical architecture components of the search system
Design Search Architectures for Microsoft SharePoint Server 2010 - This model describes the steps to determine a basic design for a SharePoint Server 2010 search architecture.