a question came up today at one of the it pro windows 7 sessions today about applocker - whether you can setup an applocker policy on windows 7 professional. here's the answer - straight from the windows 7 professional help for applocker (you can setup applocker from the local computer policy on windows 7 professional)
applocker is available in all editions of windows server 2008 r2 and in windows 7 ultimate and windows 7 enterprise. windows 7 professional can be used to create applocker rules. however, applocker rules cannot be enforced on computers running windows 7 professional. organizations should use applocker for all computers that support it.