Golden State scores about 4.5 ppg less on the road than at home, while giving up 8.5 more ppg, for a 13 point swing. I don't think Cleveland covers that 15 point spread in this game though.
Have you seen the Warriors play this year? More to the point, do you have any idea what their roster looks like right now? I've watched most of their games this year, as well as the last several years, and I would not bet them to win this game even if the odds were +1,000,000. Here's tonights roster:
PG - Curry
SG - Ellis (Agent working on trade)
SF - Morrow
PF - Randolph
C - Mikey Moore
Bench - Maggette (Nelly had him playing C vs the Knicks), Radmanovich, Raja Bell (already scheduled his wrist surgery but he's suiting up so the W's have the minimum 8 players)
Don't be surprised if Cleveland gets 60+ points in the paint with the ridiculous frontcourt matchups the W's are going to put on the floor.