What exactly sets the look of a typical Leica lens apart from other top quality? In the recent article it was mentioned that someone knew from looking at the prints, it was a Leica - what was he seeing?

I think MR described it pretty well in his recent M8 review, but here's my comment... I would say Leioca glass has the singular combination of being both very sharp and very smooth at the same time, while being able to maintain that smoothness into the oof areas (excellent Bokeh).

Yes I read the review, but I'm not clear on specifically what part of an image to identify with...like, look here at this, and notice this...

All lens designs are "colored" and some designs make more attractive images than others. This has to do with the shape of the lens OTF (optical transfer function). Leitz lenses are sharp, but what makes them distinctive is their tonal curve - contrast, namely deep blacks. It is actually not the most accurate optics BTW, but attractive nonetheless. BTW... it is fairly easy to simulate the various optics'looks in post-processing these days. Want the Leica look? create a slight S-curve with a good toe on the blacks-end.

I would say it is more about mythologizing than any real difference. I've used Carl Zeiss, Rodenstock, Schneider, Nikkor, Rokkor, Hexanon, Sekor, Fujinon, and a host of other optics. Show me a picture and I wouldn't be able to tell you if it was taken with Leitz optics.

Good optics are important. They do make a difference. But I have never found any particular manufacturer has an optical "signature." Except maybe Holga/Diana and Lens Babies.

I can spot them, they have a special snap, and out of focus areas a glow.

I must admit that a lens that has much of the same quality is the Pextax screwmount 50 1.8 for the k1000.

Ziess lenses (not the ones on the new digital point and shoots) have a quality all their own to.

Go to museums with photography on show... ones eyes will become seasoned to the finer points! Ten years ago I thought wine was wine... now I can honestly discern some of the snooty mumbo-jumbo the wine snobs go on about.

It all only maters if you notice...
I have yet to have noticed that a $30,000 Bang-Olufson is worth it...
I can that my Caddi is a better car than an Impala!