What I wonder is "how" ... Javascript? Flash? Neat tool ...

I didn't check, but yeah they use mostly DHTML (HTML + CSS + JavaScript) along with AJAX plus a couple of hacks.

Clever stuff. It's perhaps a bit off-putting from the main purpose of Maps, though.

It looks like it is completely replacing the old info page where you clicked on the title and it took you to a new page to display that information. This way at least you don't get completely removed from the map interface to see the information. That's quite an improvement.

I would prefer more EXACT info. When I visited Chicago earlier this year Google Maps sent me to a street address that was like 10 blocks away on the same street because Google showed the street number in the wrong place on the map.