.NET 3.5 SP1 includes several significant performance optimizations and improvements to WPF. Some of the specific graphics improvements include:
SP1 also adds support for better data scalability in WPF. The ListView, ListBox and TreeView controls now support "item container recycling" and "virtualization" support which allows you to easily achieve a 40% performance improvement with scrolling scenarios. These controls also now optionally support a "deferred scrolling" feature which allows you to avoid scrolling in real time and instead wait until a user releases the scroll thumb (the default scrolling mode in Outlook). This can be useful when scrolling over very large data sets quickly.