The costs of consumer devices

An interesting day spent at the first UK CIO Summit.
Much conversation about the impact of consumerization in software services (Cloud) and also in terms of devices (Apple in particular), and an underlying assumption that both would lead to lower costs. Whilst commoditization of software services in the world of SaaS undeniably does lead to lower cost-per-head, key to to the model for most vendors is a flat pricing structure (so much, per user, per year). That's great for small to mid-sized operations, and still gives cost savings to large-scale organisations, but the economies of scale are shared across everyone.
When it comes to consumer grade devices, however, I think that the cost profile is very different. Staff are going to want an iPad alongside their iPhone and their laptop, will expect it to be supported by their IT department (where most of the cost of ownership lies anyway), will want it upgraded every year (know anyone still using a version 1 iPhone?), and (even if you are buying in bulk) Apple aren't going to give you any volume discounts for any of this stuff anyway.
For some time I've been seeding the idea of an IT allowance for staff, similar to a car allowance. A fixed amount given each year for devices, which is completely at the discretion of the individual to spend. If you want a brand new iPad, fine. Buy it youself. As long as you come to work with something appropriate to work on, you can get whatever you like. Lose it or break it – replace it yourself. Really want the latest? Pay for it out of your own money.
If a company can provide all of the applications that somebody needs through a browser, this is now a possibility. Licensed software required to be installed locally on a device is the only thing that now holds us back…