I'm applying Eclipse Europa, which also has the Favorite decision section:
Window > Preferences > Java > Editor > Content Assist > Favorites
I have the subsequent entries (when combining, use "New Type" and omit the .*):
org.hamcrest.Matchers.*
org.hamcrest.CoreMatchers.*
org.junit.*
org.junit.Assert.*
org.junit.Assume.*
org.junit.matchers.JUnitMatcher.*
All but the third of these are static imports. By holding those as favorites, if I type "assertT" and hit Ctrl+Space, Eclipse allows up assertThat as a recommendation, and if I choose it, it will add the precise static import to the file.