The idea of a Cloud Desktop is appealing, but can it exist?
Microsoft does not allow service provider licensing for Windows 7. You can have a monthly subscription for a remote desktop on Terminal Services running on Windows Server, but not for Windows 7. This has been clarified recently in a note from Microsoft: Delivery of Desktop-like Functionality through Outsourcer Arrangements and Service Provider License Agreements.
Terminal Services mean that the user shares the resources of the server with other users. To be reliable it needs to be very tightly controlled. The user cannot be an admin and cannot install software. The user cannot access high quality graphics, video and audio because they do not have direct, exclusive, access to the hardware.
Note that "The hosting hardware must be dedicated to, and for the benefit of the customer, and may not be shared by or with any other customers of that partner". This is very curious. It means that you can buy a Windows 7 remote desktop running on a PC blade in a datacenter, but not on a VM (unless that also runs on dedicated hardware), even though Microsoft receive exactly the same license fee in both cases.
This is obviously an artificial restriction. One possible reason for this could be that Microsoft will soon introduce their own Windows 365 online desktop. A Windows 365 online desktop makes a lot of sense when used with Office 365, because all the data is then highly connected. You really can connect from nearly anywhere, with nearly any type of device.
At the moment with Office 365 that is not the case. Microsoft say that: "Because this infrastructure is located online, you can access it virtually anywhere from a desktop, laptop, or mobile phone". You can access it, certainly, but you can use it properly only if the PC or Mac has Office installed locally.