The part of the announcement which surprised me was the announcement that there would be a "Feature of the Day" starting in September; I thought that, usually, "Feature of the Day" only occurred for major releases and not service packs. Let me say though: this is not a complaint!
In SP2 the Web Client will see the see releases for the Project, Manufacturing and Field Service series as well as the expansion of ISV Extensibility to allow Visual Studio forms to be presented in the Web Client in the same way as Dexterity forms.
Document Attach will be extended to allow attachments to be included in emails and to allow documents attached to cards to be rolled down to the transactions. So a terms and conditions file attached to a customer record could be rolled down to the sales invoices and attached to the email.
One really nice feature is the ability in SmartList to hide the navigation tree; here's hoping this is a button on the toolbar to quickly expand and shrink the nav pane.
For full details of the announcment check the original blog post.