Well, now that I know a mono-Dark run on my Pokemon Black game is possible, I'm going to likely try for a pure run, later on this upcoming months. I do have a few caveats, though: except for a few Dream World pokemon, I'll only be using Pokemon I can actually get in the game, so nothing like a starter Poochyena or anything. The only exceptions will be Carvanha and Murkrow (so I can have a surfer and flyer on my team, respectively), but they won't be acquired until after I get the requisite HMs for them (Surf and Fly, again respectively). As such, my team will likely be made up thusly:

Purrloin
Zorua
Scraggy
Sandile
Carvanha
Murkrow

This will be subject to change, as I get more and more Dark-types, so just be warned. Dunno if I'll do this on a DS emulator as an LP or what, but I'm definitely going to be doing it. If I DO do it on an emulator, be warned that I WILL be hacking into the game to get Zorua, Carvanha and Murkrow at the proper times, and will likely do so to get a Purrloin with its Dream World ability, but that would be IT for cheating.

Give me your thoughts on this, if you would; I'd appreciate any constructive feedback you can give on this.