Ive just started a PC support role, and across the many branches I support, they are rolling out thin clients to every user.
To the non nerdy folk, its basicall a "box" that sits next to a monitor and keyboard but has no hard drive or things like that and just communicates with a server for all the applications/programs etc, and can be configured remotely.
Of course they will go down, as will the monitors/keyboards, new install required etc .. But as for job threat?
Possibly..