Good news - SQL Server Compact Edition has been released. This is a new offering of SQL Server based on SQL Server Mobile that will run on mobile devices (Pocket PC and Smartphones) as well as on Windows XP and Windows Vista.
From the download page:
Microsoft SQL Server 2005 Compact Edition (SQL Server Compact Edition) is designed for developers who need light weight, in process relational database solution for their applications that can be developed and deployed on desktop as well as on mobile devices. SQL Server Compact Edition Runtime can be used to develop and deploy applications on desktop.
SQL Server Compact Edition is a powerful, yet lightweight relational database engine that makes it easy to develop desktop applications by supporting familiar Structured Query Language (SQL) syntax and providing a development model and API consistent with SQL Server. When compared to its previous release, SQL Server Mobile, SQL Server Compact Edition includes new features like |DataDirectory| and ClickOnce support for ease of deployment (Please see SQL Server Compact Edition Readme)
This release has several key features that enable ISV’s, developers and administrators to develop and deploy their offerings seamlessly and we believe is a compelling offering from the SQL Server family in this space:
1. Tight integration with Microsoft Visual Studio 2005 as well as the .NET Framework and support for a familiar query syntax and common programming model make for a consistent developer experience.
2. Click once compatibility enables easy deployment and Microsoft Update integration allows for simple maintenance plans.
3. Integration with business intelligence features allows for extending business insights across the organization to data sources in distributed and mobile applications.
4. Synchronization services to SQL Server enables distributed occasionally connected applications to take their data anywhere, anytime, anyplace.
It is a 1.7 Mb download available from here.