Hi Serge,
Would you mind changing folder name of this one from shopping-cart to helloworld-sfsb to match the quickstart short name. I don't think the instructions were clear here: https://docs.jboss.org/author/display/AS71/Writing+a+quickstart, so I just modified them to be more specific. The reason for this is the short name is more descriptive of the technology it demonstrates and it will be easier for developers to find.

Can you also modify the readme to follow the new standard described on the page above? That means the title would read:
helloworld-sfsb: Stateful Session Bean Example

The pom.xml versions need to be updated to 7.1.0.Final because I successfully deployed the server side, but when I ran the mvn exec:exec, I got the following error:

client (helloworld-sfsb) $ mvn exec:exec
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building JBoss AS Quickstarts: EJB Remote Client 7.0.2-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- exec-maven-plugin:1.2.1:exec (default-cli) @ jboss-as-shoppingcart-client ---
Feb 19, 2012 7:35:04 PM org.jboss.ejb.client.EJBClient <clinit>
INFO: JBoss EJB Client version 1.0.1.Final
Feb 19, 2012 7:35:05 PM org.xnio.Xnio <clinit>
INFO: XNIO Version 3.0.0.GA
Feb 19, 2012 7:35:05 PM org.xnio.nio.NioXnio <clinit>
INFO: XNIO NIO Implementation Version 3.0.0.GA
Feb 19, 2012 7:35:05 PM org.jboss.remoting3.EndpointImpl <clinit>
INFO: JBoss Remoting version 3.2.0.CR9
Feb 19, 2012 7:35:05 PM org.jboss.ejb.client.remoting.VersionReceiver handleMessage
INFO: Received server version 1 and marshalling strategies [river]
Feb 19, 2012 7:35:05 PM org.jboss.ejb.client.remoting.RemotingConnectionEJBReceiver associate
INFO: Successful version handshake completed for receiver context EJBReceiverContext{clientContext=org.jboss.ejb.client.EJBClientContext@1d10a5c, receiver=Remoting connection EJB receiver [connection=Remoting connection <176cad3>,channel=jboss.ejb,nodename=localhost]} on channel Channel ID 94b64cbe (outbound) of Remoting connection 011ca803 to localhost/127.0.0.1:4447
Feb 19, 2012 7:35:05 PM org.jboss.ejb.client.remoting.ChannelAssociation$ResponseReceiver handleMessage
WARN: Unsupported message received with header 0xffffffff

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
Obtained a remote stateful counter for invocation
Buying 1 memory stick
Feb 19, 2012 7:35:06 PM org.jboss.ejb.client.remoting.ChannelAssociation$ResponseReceiver handleEnd
INFO: Channel Channel ID 94b64cbe (outbound) of Remoting connection 011ca803 to localhost/127.0.0.1:4447 can no longer process messages
Exception in thread "main" java.lang.NullPointerException
	at org.jboss.ejb.client.remoting.ChannelAssociation$UnusableChannelResultProducer.getResult(ChannelAssociation.java:363)
	at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:212)
	at org.jboss.ejb.client.TransactionInterceptor.handleInvocationResult(TransactionInterceptor.java:47)
	at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:214)
	at org.jboss.ejb.client.ReceiverInterceptor.handleInvocationResult(ReceiverInterceptor.java:96)
	at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:203)
	at org.jboss.ejb.client.EJBClientInvocationContext.awaitResponse(EJBClientInvocationContext.java:341)
	at org.jboss.ejb.client.EJBInvocationHandler.doInvoke(EJBInvocationHandler.java:126)
	at org.jboss.ejb.client.EJBInvocationHandler.doInvoke(EJBInvocationHandler.java:107)
	at org.jboss.ejb.client.EJBInvocationHandler.invoke(EJBInvocationHandler.java:90)
	at $Proxy0.buy(Unknown Source)
	at org.jboss.as.quickstarts.client.Client.main(Client.java:74)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.322s
[INFO] Finished at: Sun Feb 19 19:35:06 CST 2012
[INFO] Final Memory: 3M/56M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (default-cli) on project jboss-as-shoppingcart-client: Command execution failed. Process exited with an error: 1 (Exit value: 1) -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

This is the server console:
19:38:22,940 ERROR [org.jboss.as.ejb3.remote.protocol.versionone.VersionOneProtocolChannelReceiver] (Remoting "localhost" task-1) Exception on channel Channel ID 4228a28e (inbound) of Remoting connection 01fa4c4b to /127.0.0.1:47336 from message org.jboss.remoting3.remote.InboundMessage$3@69cb41: java.io.StreamCorruptedException: Unexpected byte found when reading an object: 0
	at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:750)
	at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:209)
	at org.jboss.marshalling.AbstractObjectInput.readObject(AbstractObjectInput.java:37) [jboss-marshalling-1.3.9.GA.jar:1.3.9.GA]
	at org.jboss.as.ejb3.remote.protocol.versionone.MethodInvocationMessageHandler.processMessage(MethodInvocationMessageHandler.java:156)
	at org.jboss.as.ejb3.remote.protocol.versionone.VersionOneProtocolChannelReceiver.handleMessage(VersionOneProtocolChannelReceiver.java:170)
	at org.jboss.remoting3.remote.RemoteConnectionChannel$5.run(RemoteConnectionChannel.java:435) [jboss-remoting-3.2.2.GA.jar:3.2.2.GA]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_25]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_25]
	at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_25]