Roddicks power has gone down overall. He used to be comfortably be the fastest serve in the game, now hes 3rd or 4th. His max now is usually about 220kmh unlike the regular 230+ we saw a few years back.
To be fair he's putting a greater emphasis on placement and 1st serve % now. He's better off serving at 140 mph rather than 150 mph if he can get just as many aces/unreturnables and a higher 1st serve %. I don't know offhand his serving stats from 2003-2004, but I'd be surprised if he really was able to produce significantly more service winners than modern Roddick.
Look at the serving stats on the Aussie Open website. Roddick has the 7th highest 1st serve % of the tournament at 71%. That's incredible for a guy with such a strong serve. It's that type of consistent serving that allowed him to almost pull off the Wimbledon title last year.
The weaker forehand is disappointing, though. He'd be much better off if he could bring that back.