>Why would it be useless? If I configured an application to poll the webservice every 5 minutes, and check if there were new messages in an forum. How would the be uselees?

It would be useless because you'd probably always get a notification every 5 minutes as messages are created quite fast here during the day. That'd be ok if only 5-10 messages a day would be created. So, yes, it'd work. But, just for today, you'd be notified at every time. That will also increase as months go by in this forum as the .NET traffic will increase.

>I've seen the email option, but I don't want to be swamped by even more email, and as you pointed out the GetReply() Method is available to PUTM only.

You probably never saw the content of such email. I can tell you that what you see here when reading this message is exactly what you'll get by email. There's a lot of fancy options on the Universal Thread. Basically, so far, we succeeded to respond to most of the needs where most of those options are quite unique.