I've just added a basic query tool feature to ServerTools->DbTools - right click on a logical db connection in the Server Explorer -> Database Explorer node, and 'Open SQL Tool' is available as an option. This opens a Form hosted in a ViewContent with three tabs - one is an editor based on #D's TextEditorControl, the next hosts a DataGridView of the result set from any successful execution of the SQL entered in the editor, and the last hosts a TextBox which shows any messages or exceptions encountered.

Right clicking on the text editor presents the option to dispatch the SQL to the server identified by the Database Explorer node from which the SQL Tool was opened.

 The next feature I am planning to implement is SQL parsing and field name completion.