The full edition Profiler can connect to Express and it can monitor it's execution. Another venue is to use the DMVs, specially sys.dm_exec_query_stats
and sys.dm_exec_requests
. The former gives information about past query execution time, whether the query was CPU bound or not, how much IO it performed. The later gives information about currently executing queries, specially what they are currently waiting on and how much IO they are performing. It takes a good understanding of things SQLish to interpret the results, but all the information is out there in the DMVs and they can be queried on Express using any query tool, like Express's lite SSMS or even from sqlcmd.