A medium instance -- the size I tested -- has four virtual CPUs, 8GB of RAM, and 400GB of storage for $500 a month. If you want to buy by the hour, it's 5.5 cents per virtual CPU per hour, 7 cents per gigabyte of RAM per hour, and 30 cents per gigabyte of storage per month. Once you reserve this hardware, you can then split it up into VMware virtual machines, just as if you purchased a real piece of hardware and installed VMware.
Virtualization and freedomThe biggest difference about Dell may be in the openness to the virtual machine part of the stack. All of the other major cloud companies take your money and give you root on some virtual machine. Then they pretend that much of the virtualization isn't there. The root password makes it look as if you're logging into your very own box, when in reality you're logging into a virtual machine that's sharing one piece of hardware with a bunch of other customers.
With Dell, you open up your Dell Cloud portal and find a VMware vApp, described by one Dell support engineer as the equivalent of a rack where you can stick your own virtual machines. To fill the virtual rack, you can draw on a few standard templates to create an F5 load balancer, a Windows Server 2008 R2 machine, or a Suse Linux 11 box, but of course you're also welcome to upload any VMware or OVF virtual machine.
There's also an option for starting up a machine with a particular ISO file -- useful if you want to boot up a particular LiveCD version of Linux or any other OS. The portal even lets you pretend that you're accessing the CD/DVD drive on your machine though you're just uploading ISO files.
The ability to poke around at this level is liberating. You can mess around with a virtual machine on your desktop using VMware Workstation or VMware Fusion, then upload it to your virtual rack and start it up in the server farm. Most of the other clouds let you create images of your servers, but usually you end up doing the work to build the image on their machines.