Amazon(s amzn) and Microsoft(s msft) are definitely partners — users can run  a bunch of Microsoft software on AWS — but the companies are increasingly at odds now that Microsoft Azure has AWS-like Infrastructure-as-a-Service capabilities. That’s probably why Microsoft added Amazon to the list of the dis-invited for its annual Worldwide Partners Conference where Amazon joins Google(s goog), VMware(s vmw), Salesforce.com(s crm).

Shutting out competitors from vendor trade shows is nothing new — here’s the VARguy’s story on last year’s WPC no-gos. And earlier this year, VMware refused to let partners Nutanix and Veeam  into its partner event. But the supreme example of a spectacular snub came a few years back when Oracle(s orcl) CEO Larry Ellison famously cancelled a keynote by Salesforce.com CEO Marc Benioff  scheduled for Oracle OpenWorld. The issue? Salesforce.com is a huge Oracle partner and customer, but also a die-hard competitor in enterprise applications.

So all this invite/disinvite stuff is…