Hey Bodhi,
Mirage could be used, as you said, to manage booth, physical and virtual Workstation. IMHO the focus is still on the physical ones, because of the possibility for Migration from WinXP to Win7 inPlace (maybe that will help you with your WinXP Enviroment in... the near future ^^) or the excellent disaster recovery for lost or damaged Endpoints.
in such a scenario you could easily transfer the user data (including Software etc.) to a virtual enviroment.
But back to your "rchaic process":
What could you do with mirage there?
First there is a Whitepaper / Guide to develop a WinPE with the Mirage Agent on it. This WinPe could be used to boot from an usb device an connect the endpoint (Thick Client) to the Mirage network.
As soon as it is connected you can assign a "Core Image" to that endpoint. This is similar to the ghost image but even offers more than an ordinary imaging. for example you could create one Image containing all your software. addional to that you could create a driver library for each type of your endpoints (different HW vendors etc.) so you just have to maintain one image (hoepfully^^)
so as soon as you assign a Core Image to the endpoint you could also assign a drivers library and it will be "merged" together. The Agent will transfer the data to the endpoint and do all the stuff like domainjoin etc.
On top of that you'll able to assign already collected /centralized (serverbased) userdata to that endpoint. so a user could login as soon as the core image is deployed. it is really working very well, i saw it in a project we did with that software.
If have any furhter questions feel free to ask, i'll try my best...
Greetings