A goddess of lies and treachery who reveals her true form shouldn't still be remotely attractive. The contrast between "beauty" and "beast" is not as effective if the beast is just going to take a few more beers.
But that's the lover of mythology in me. The marketer in me, who is aiming for D&D's teens-and-twenties dorky dudes demo, would want to put as many boobs all over every book as humanly possible.
"I don't wanna see five pages go by without at least one T&A shot! Breasts should be spilling out of this thing!"
I'm comfortable with WotC's current middle-of-the-road approach. Lolth still looks badass, and it's easy enough to change her to more horrific in the home games.
Edit: About the Drider Curse? I'm okay with it being both ways. Driders are cursed forms for failing the Goddess. The Goddess herself has this cursed form. It is the form she was cursed with when she betrayed Corellon and the rest. She doesn't like it. She doesn't want it. She does everything in her power to overcome it. Only those who erode her might enough so that she can't maintain her lies get to witness it. In order to express her contempt for those who fail her, she gives them what she loathes the most: this vile spider form. It wasn't a blessing when she was forced into it, it's not a blessing when she gives it to others. In this concept, the Drow themselves hate warping their bodies in any way (no tatoos, no polymorphs, kill those with birth defects), because their bodies are a sacred form. For Lolth to be robbed of that form -- or to rob another of that form -- is to steal from them their divine essence, the thing that makes life worth living, being a drow. Now they are some other hideous monstrosity, and this does not suit them at all.