Or are you thinking of something else? I want to understand the use cases...
I was not thinking about anything that complicated, although I like your train of thought! As mentioned by atrax27407 there are already various methods of getting software to a P-Box. For the benefit of newbies I'll list a few of them here:
1) Via RS-232 (various methods)
2) Via diskette (provided you have an obsolete computer with disk format compatible with and capable of using the program)
3) Via HxC or similar device
Sadly not everyone has an RS-232 card, an HxC type device or the ability to make TI compatible diskettes on the PC. Looking ahead I believe that Ralphb's FinalGROM99 is going to be quite the popular device among EVERYONE. Newbies & returning TI'ers will want it for it's ability to do so much without a P-Box, advanced users for it's speed and utility. As we've witnessed over the years, many returning TI'ers get the upgrade bug, so I'm figuring the FG99 could be the right tool already in their toolbox for this specific job as well.
A use case with the concept laid out... (fictional future scenario)
User "T. I. Fanatic" just bought a new P-Box, from eBay, but it's useless to him. He cannot get any files from the Internet onto his newly acquired P-Box's 5.25" 90K disk drive. Lucky for him he has the FG99 he bought 6 months ago when he was getting back into the TI. What is he gonna do? Simple, TI user, "Uber Programmer" wrote a two part suite of software that covers that!
Step #1 is the PC program. You load it and "drag" all the TI files you want into it's window. When you are ready, press EXECUTE. The program then combines a TI loader routine into a single package with the TI files for transfer.
Step #2 You take this TI program created by the PC, and put it on the FG99's SD card.
Step #3 Select the file and run it. To the TI the program appears to be like any other disk manager program, except in this case the data is coming off the TI and out of this special program itself.
Sure, it's essentially a one time use program (unless you want to keep it as a backup), but I imagine a PC can stitch something like the required program together in mere seconds.