smithaa02 - 1:16 pm on Oct 3, 2011 (gmt 0)
I suspect that google can handle multi-word urls somewhat ok depending on the context. They know a lot of people are using CMS's like wordpress that can inadvertently spawn large urls, so I don't see them punishing this. However, it does seem clear if your URL has a lot of keyword repetition (like the baseball card example) this is probably bad.
I do think all things being equal the short url will trump the long url. If you have two pages, brandons-old-baseball-cards.html and baseball-cards.html I suspect the latter (all things being equal) would rank better for baseball cards because it's keyword concentration in the URL (my theory) is superior. Google knows your url has to be unique, so I suspect they divide up it's 'ranking power' by its length for starters discourage double-dippers and spammers and secondly a concentrated short url is more likely to be a general on-topic page that google is looking for.
If you do a generic search in google (pick say a bunch of animal) in my experience, the best search results have been short urls.
I got the impression from the google docs as well as other sources that /brandons-dodgers-baseball-cards.html is treated somewhat similarly to a directory separated url like /brandons/dodgers/baseball-cards.html. In my opinion directory structures too should be short and sweet to improve keyword concentration in the URL.