The SharePoint Online Standard Developer Guide is now available for download at http://www.microsoft.com/downloads/details.aspx?FamilyID=d007f35e-375c-4b11-bc40-bc9082bb224a&displaylang=en. Some of the main topics covered (and tested) include:
1. Customization capabilities and limitations.
2. Custom templates, master pages, style sheets.
3. Data Form Web Parts (adding, editing, deleting, sorting, filtering list items).
4. The 20 site admin templates of the fantastic forty (the other 20 are of type server admin templates and require custom code) are tested and they work with SharePoint Online.
5. List of supported and unsupported SharePoint Online web services.
6. Integrating Microsoft Silverlight with SharePoint Online.
7. No-code Workflows using SharePoint Designer.
8. Code examples and scenarios as appropriate.
Also, an update to the SharePoint Online Standard Service Description document has been published at http://www.microsoft.com/downloads/details.aspx?FamilyID=1bef6a35-9785-4a0b-b227-387c0ee85a36&DisplayLang=en. This update includes a matrix comparison of SharePoint Server 2007, SharePoint Online Standard and Dedicated offerings.