I'll take the term "vendors" to mean software vendors. Like all "hype-driven" computing standards, basically everyone is signing up with Web services, including business application vendors, application integration vendors, application development vendors, even office automation vendors. It's similar to the Web back in 1995.
The approach each vendor takes varies greatly. However, application integration vendors all seem to be exposing their application integration subsystems as Web services, albeit they will do this using different mechanisms and varying degrees of success. Application development vendors are enabling their tool sets to create and leverage Web services.
As 2002 closes, we'll be able to better to answer your questions. Right now it's difficult to distinguish the vapor from the real products.
This was first published in March 2002