You can use non-GTalk server just for transport services; you don't even have to have an account on that server. For example,
jaim.at. However if you do use
jaim.at or
msn.jaim.at or some other transport server with Google, be aware that it'll spam your account with all your other-service contacts, which you probably don't want to do.
Luckily, Jabber provides extremely simple account registration, so I think it should be no problem to register a test account on
jaim.at :)
Regarding the bug, yes, apparently I can see the "Services" submenu now. However restart of Kopete is required for the new virtual "account" to appear in the account list on bottom of the window. Also none of the transport-specific contacts appear. I have tested with MSN and ICQ transports at Jaim.at. When using Psi, at least my ICQ contacts do appear (and I get asked for confirmation to authorize adding them to my contact list).