I should talk about this more. SQL filters and rules on Service Bus Topics subscriptions. SQL action syntax http://msdn.microsoft.com/en-us/library/windowsazure/microsoft.servicebus.messaging.sqlruleaction.sqlexpression.aspx

sqlfiltersandrules.cs

namespace SqlFiltersAndRules
{
    using System;
    using Microsoft.ServiceBus;
    using Microsoft.ServiceBus.Messaging;

    class Program
    {
        static void Main(string[] args)
        {
            var nsm = NamespaceManager.Create();
            
            string ruletestName = "ruletest";
            if (nsm.TopicExists(ruletestName))
            {
                nsm.DeleteTopic(ruletestName);
            }

            nsm.CreateTopic(ruletestName);
            nsm.CreateSubscription(ruletestName, "sub1", new FalseFilter());
            var sc = SubscriptionClient.Create(ruletestName, "sub1");
            sc.AddRule(new RuleDescription
                {
                    Name   = "rule1",
                    Filter = new SqlFilter("sys.SequenceNumber % 2 = 0"),
                    Action = new SqlRuleAction("SET ThisMessageIs='Even'; SET FullName = FirstName + ' ' + LastName;")
                });
            sc.AddRule(new RuleDescription
                {
                    Name   = "rule2",
                    Filter = new SqlFilter("sys.SequenceNumber % 2 <> 0"),
                    Action = new SqlRuleAction("SET ThisMessageIs='Odd'; SET FullName = LastName + ' ' + FirstName;")
                });

            var tc = TopicClient.Create(ruletestName);
            tc.Send( new BrokeredMessage { Properties   = {{"FirstName", "Clemens"}, {"LastName", "Vasters"}}});
            tc.Send(new BrokeredMessage { Properties = { { "FirstName", "Abhishek" }, { "LastName", "Lal" } } });
            tc.Send(new BrokeredMessage { Properties = { { "FirstName", "Ziv" }, { "LastName", "Rafalovich" } } });
            tc.Send(new BrokeredMessage { Properties = { { "FirstName", "Ruppert" }, { "LastName", "Koch" } } });

            for (int i = 0; i < 4; i++)
            {
                var msg = sc.Receive();
                Console.WriteLine("{0} {1}", msg.Properties["ThisMessageIs"], msg.Properties["FullName"]);
            }
            Console.ReadLine();
        }
    }
}