I also agree with these comments - I can't think of any simple way for LMCE to automatically detect if this is a "casual" device or something more permanent. But certainly, the average consumer would expect the option to simply "import" the contents, perhaps with a "chooser" of somekind so you can at least choose the right folder (eg DCIM, on cameras, and so on) or better yet, highlight individual pics, songs, etc.
The problem I see is that the wizard that pops up now, is already a little confusing as to which option does what (using the LMCE structure, or not, and the other questions). Perhaps prior to those questions, a simple one should be added along the lines of "I have detected that new media storage has been connected - do you wish to Import the Contents so that you may disconnect it again, or leave it connected and Merge the Libraries together? -> Import Contents/Merge Libraries"
That was off the top of my head, and definitely needs to be reworded, but you get the picture! The first option would go into the new script that Andrew is talking about, the second would go into the normal script - perhaps that normal one should be reworded as well?!
This could be generic for all discovered media devices, even PCs etc permanently connected to the network. Maybe you don't want to add your PC to the LMCE environment permanently, but do have a share of media on it that you want imported into the LMCE libraries (a PC that isn't normally on the Internal network, or a friend's/work laptop, etc) - at least this way you could bring all that media into your system "casually", and then remove the PC (or even leave it) without having to go into the admin console, find it and manually remove it because it was never added as a system but the auto detect scripts...