From JOPX Blog
1. Built on top of ASP.NET 2.0
- Web Parts (But also master pages, provider model, ….)
- Site template with behaviors + different components (web parts, lists, etc …)
- Use plain ASP.NET 2.0 when you really need full control on all aspect of the platform. When reproducibility/reusability is a key use WSS or MOSS
- Web part manager, web part zones – ootb present in WSS/MOSS
2. Data, metadata, features, content types …
- Rich Object Model
- Features – possible to hook up your own code and UI – activate and deactivate features – more flexible model
3. InfoPath Forms Services
- Forms are everywhere
- InfoPath Forms Services offer server side generation and handling of forms
4. Workflow
- Workflow technology
- Business run on business processes
- Succesfull executing business process is a key success factor for companies
- Easier for developers – provide another layer of abstraction – easier to visualize complex software problems
- More time on business process development and less on plumbing (state management, etc …)
- Code creap – with every change – easier to build modular software
5. Excel services
- Great charting and calculation engine
- Now server-side calculation engine available for browser based spreadsheet viewing & interactivity (It's like DDE all over again but this time on a scalable server platform)
6. Business Data Catalog (BDC)
- XML metadata driven engine to integrate your backend systems (CRM, ERP systems, …)
- OOTB web parts present – Business Data Detail WebPart, Business Data List Web Part, …
- Will evolve into Line of Business Integration (LOBi) and Office Business Entities (OBE) – unification of the programming model on the client and server side of Office
7. Lots of other stuff : document and storage enhancements, Business Intelligence solutions possible, multi language support, wikis and blogs, …