To add Live search results to your existing SharePoint page that contains the search results web part:
The first thing is to sign up an Application ID for and download the SDK from http://search.msn.com/developer/default.aspx?FORM=PDDD2
The next thing is to backup any custom XSL rendering and fields from your Search Summary web part because SharePoint Designer (SPD) may corrupt your custom XSL (as it did for me, trying to preserve white space).
Add a Web Service to the Data Source Library using SPD
Double click on the *Request parameter and set the following values
Click OK then click on the data source and select 'View Data'.
Right click on the Result node and select 'Insert as Table'. Then click on the Common Data View Tasks arrow (little arrow to the right of the data view web part) and create the parameters that will be extracted from the URL and passed to the Live search web service as shown below
You can also change the columns used in your web part and the layout to match the view shown above.
Note: Your server must be able to access the Internet for this to work. This may require setting up a proxy setting in the web.config file. If the RSS web part can't display and Internet RSS feed then this isn't going to work either.