Absolutely yes. More details:

http://blogs.msdn.com/psssql/archive/2009/09/11/fun-with-locked-pages-awe-task-manager-and-the-working-set.aspx

I am going to take a look at the execution plans now. Note to Barry: the optimizer never considers how much Buffer Pool is available when constructing a query plan. It does save the minimum amount of memory required, and a 'desired' amount however. If less than half the desired memory grant is available at run-time, the request will wait in the memory grant scheduler queue. The maximum wait time is 25 times the estimated cost of the plan, in seconds. Error 8645 is raised if this time-out is reached.