The Grumpy Editor's GNOME 3 experience

Nope. The hot corner is just 5x as annoying for anyone using a laptop with a wireless mouse where the mouse happens to get bumped around a lot. (Like, say, when it's on the armrest of your couch.) And when your trackpad is not ideal because it's located in the "your palm always hits it" space or you have an ASUS where the touchpad being enabled causes the keyboard to miss keystrokes, or you just happen to prefer a mouse over a trackpad.

Win7 has an option to show desktop on a hot spot in the bottom right, which is on by default. It's infuriatingly obnoxious on my laptop (I don't notice it at all on my desktop, of course) and I have disabled it. It's nice and logical where it's at, too: right-click on the show desktop button in the bottom right and unclick "peek at desktop." (The name of the option is horrible/confusing, but the location is the first place I thought to look.)

GNOME 3 on the other hand is just going to remain infuriatingly unusable for me on my laptop until that hotspot behavior gets turned into an option.

The corners work so well as a hotspot for desktop users specifically because it's so easy for a pointer to end up there. When your pointer is not always moving due to user desire, however, that pointer-gravity works against you rather than for you.