Antares is a hosting framework for Web applications and sites created using various languages and stacks -- including a number of open-source, non-Microsoft-developed ones. Microsoft's goal is to make this hosting framework available for both the cloud and on premises on Windows Servers, so that companies can use it as a hosting environment for public or private cloud sites and apps.
The Linux VM capability, as I outlined earlier this year, will provide Azure with infrastructure-as-a-service components, allowing it to compete more effectively with Amazon Web Services. Azure customers currently can run Linux on Azure via the VM role, but the VM loses any data stored (any persistence) whenever it is rebooted or randomly recycled by Azure. Making the VM role persistent would also provide Azure users with a way to run SQL Server and/or SharePoint Server and apps based on those servers on Windows Azure.
According to Microsoft's "Meet Windows Azure" site, the plan seems to be for Corporate Vice President Scott Guthrie and some of his team to share some information on June 7, and then follow up with more technical details on Azure to come at TechEd North America, which kicks off on June 11.
Guthrie heads the Azure Application Platform Team, which oversees ASP.Net, IIS, IIS Media Services, Windows Workflow, Windows Communication Foundation, Service Bus, WebMatrix, NodeJS and other developer-centric cloud technologies. According to Microsoft's jobs site, the Azure App Platform Team has over 600 engineers.