MIX09: Workshop Clinics on WPF and Silverlight

The IsSearchProviderInstalled API is rendered mostly useless by the following condition: "Sites are only allowed to search for providers on the same domain." This eliminates the ability for, say, microsoft.com or msdn.com sites to determine if an Internet Explorer user has added a Live Search search provider (live.com).
The AddSearchProvider API does not provide a way to indicate if a user has opted out of adding a search provider by clicking Cancel. Additionally, because of the limitation above, there is also no way to determine if a user successfully added a search provider for a differently domained search provider.
This is tangential to this video, but the Live Search autocomplete suggestion Web service does not provide a way to scope suggestion results to a particular domain.
You can only have one default search provider but you can install as many secondary search providers as you like.
The IE8 QuickPick menu makes it very easy to switch to any secondary provider.
We don't support aggregation of search results right now but thanks for the suggestion.