Some very good posts
I was impressed by Guerrero's physicality against Berto, and I wouldn't be surprised if he continued that against Mayweather...which would be a mistake IMO. Mayweather is just too clever, too experienced, and it's what he expects now.
The 'ambush' tactics are very interesting, and the fact Guerrero is southpaw who has very good punch variety makes it all the more interesting. What Guerrero can't do if he is to have success is throw the "norm" combinations and patterns. Don't follow a right with a left, then a right and then a left. Mix it up, throw two lefts, one right, a left, two rights, etc, etc...all the while mixing it from head to body, body to head, uppercuts, etc. Straight punches, hooks, different angles for punches, different variations of punches, etc. Don't fall in to a pattern, Mayweather loves it. Cotto had a lot of success by mixing his punches up, 3 lefts in a row, not the usual left, right, left. You will make Mayweather's defense stand out even more if your punches are in the left, right, left pattern.
Not sure Guerrero is capable of any of this though. He may have success early, but I see Mayweather breaking him down.