The creative industry uses these kinda things on a regular basis.
Whether a home user would use a whole stack, I dunno, but the option is there and I do tend to think, again, that the home user would have it in association with work.
Just as an example, one of our editing suites has like 6 or 7 Maxtor units, 500g+ each, daisy chained across the desk, with it`s obvious issues regarding seperate DC adaptors for each. This kinda thing would help here, they get swapped in/out a fair bit. Speed isn`t that much of an issue as they use firewire.
Average home user ? Nah, possibly as a kind of icybox idea, esata is nice tho, very nice infact. Home user would use 1 perhaps.
Nice`n neat tho.