I just downloaded the free version of ESXi 5.5 to start evaluating it relative to 5.1. From reading, VMware is moving to a web console only, with the native client only for 'emergency access' to the host (Why is everyone going to web consoles? they tend to be more problematic than native consoles...).
With the free version, how are you supposed to get the Web Console? There's a reference under the vSphere client download saying: 'Note: vSphere Web Client can be installed using the vCenter Server installer', but that's not available to download when you register for the free version. So if you have the free version, what's the right way to get the web client and what are you supposed to install it on? If the web console is now going to be required to access newer features of the Hypervisor, maybe VMware should consider providing the vCenter appliance with the free version, with the paid features disabled, of course.