Absolutely!

With WSE you just make sure to write your web service class as a standalone assembly (i.e. not a web project). Next step is to derive your service class from WSE's SoapService. Finally, you write all your web methods like you normally would using WSE.

As for hosting, if you want to host using soap.tcp you write a lightweight host application (console, winforms, winservice) and do the following (simple logic just for illustration purposes):

SoapReceivers.Add(new EndpointReference(new Uri("soap.tcp://<your hostname or ip>/MyService")), typeof(MyService));

For hosting in ASP.NET, all you need to do is add the following entries to a web.config:

<!-- add this to register the WSE 2.0 section handler -->
<configuration>
 <configSections>
   <section name="microsoft.web.services2" type="Microsoft.Web.Services2.Configuration.WebServicesConfiguration, Microsoft.Web.Services2, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
 </configSections>
</configuration>

<!-- then add this to register your service -->
<httpHandlers>
 <add verb="*" path="MyService.ashx" type="WhateverYourNamespaceIs.MyService, WhateverYourAssemblyNameIs"/>
</httpHandlers>

One class. Any protocol. Nice, right? Great design on WSE's part.

HTH,
Drew