After, oh, six or so attempts, I've finally defeated Pokémon Black's fourth gym leader--some hussy who calls herself Elesa.
Apparently I had been training the wrong Pokémon in the lead up to my battle with Elesa (below). That's what I get for ignoring the game's oh-so-ugly (in my opinion) ground and rock Pokémon, I guess.
Next up: The title's fifth gym leader. Oh, and more Pokémon hunting and training, of course. I'm especially looking forward to spending some quality time with my recently captured Vanillite and Whimsicott.