It's bigger than a breadbox. And you probably won't be sticking it in your kitchen this summer. But make no mistake, the "appliance" that Microsoft announced at this week's Worldwide Partner Conference is not only a technical marvel, it's concrete evidence of the depth of Microsoft's commitment to cloud computing.

If you've seen the news, you might still wonder: exactly what is the Windows Azure platform appliance? As Robert Wahbe (VP of Microsoft Server and Tools Marketing) notes in this blog post, it is a unique hardware-software offering that delivers network, storage, and computing resources based on the full Windows Azure platform stack (Windows Azure and SQL Azure). Dell, eBay, Fujitsu, and Hewlett-Packard are starting to deploy it now.

Once in the market, it will be a serious cloud offering. As Robert puts it, "Service providers, governments and large enterprises who would consider buying, say, 1,000 servers at a time, will be able to deploy and manage the appliance in their datacenter." So in addition to the massive scale and multi-tenancy that come with the Windows Azure Services platform, it offers the added benefits of control: physical location, geo-proximity, data sovereignty, and regulatory Compliance.

To get a deeper overview, I talked with Scott Ottaway, one of the key product managers on the Windows Server team who is seriously focused on the Windows Azure platform appliance:

As Scott noted, the announcement of the appliance is another milestone in Microsoft's intensive efforts to make cloud computing a reality. Here's an overview of other Microsoft info/voices out of WPC this week:

• You can read the press release from WPC, including the announcement of the Windows Azure platform appliance here.
• Robert Wahbe's blog post gives some great context on our strategy for helping businesses embrace cloud computing.
• SQL Guru Donald Farmer blogs about a new "premium information marketplace" dubbed Microsoft Codename "Dallas," which he describes as "a place where developers on any platform as well as information workers can find data from commercial content providers as well as public domain data to consume and construct new BI scenarios and new apps." Zane Adam, general manager of the Azure team, gives his take here.
• SQL Server expert Dan Jones lets you kick the tires of SQL Azure and connects you with a nifty nine-page downloadable guide to get you started.
• The Windows Server team announces that Windows Server 2008 R2 SP1 Beta is available for download.

Other voices:

• Press announcements from eBay, Dell, and Fujitsu.