This places the responsibility on theme authors to support the new classes. They are:

• alignleft
• alignright
• aligncenter

I'm not convinced of the need for the align prefix, but it's great progress nonetheless. If your theme doesn't support those classes, here's the code you can insert at the end to handle them:

.alignleft,.left {
	float:left;
	margin: 0.5em;
}
.alignright,.right {
	float:right;
	margin: 0.5em;
}
.aligncenter, .center {
	display: block;
	text-align: center;
	margin: 0 auto;
}

1. CSS House 2
2. CSS Zen Garden
3. Joshua Davis' Work for the BMW Z4
4. Mies Van Der Rohe's Barcelona Pavilion
5. Frank Ghery's Jay Pritzker Pavilion

The distinction between art and design is semantic and objective.  There is no aesthetic consideration in distinguishing one from the other.  Design always fulfills a function.  Designs succeed by functioning well while being aesthetically beautiful.  Art is an expression unto itself.  It succeeds or fails on the validity, clarity, and beauty of that expression alone.

This does not mean that designers cannot make art.  Or that artists can't design.  In fact, there is plenty of crossover, which sometimes makes the distinction difficult to judge on the surface.  The answers to the quiz rely on an understanding of each project.  If you're not familiar with each one, you'll need to read up on them in order to understand the process and ideas behind them.  Because while there is crossover, the distinction is not fuzzy.

Ugly art is still art.  Beautiful design is still design.
And yes, the starting point for this was Andy Skelton's semantically incorrect title for a post about semantics.  But it's a point that's often missed.  Usually in the form of "you wouldn't tell picasso to redesign his paintings!"  Answers will be posted as an update.