Roddick is capable of a good day/big win, but doesn't seem consistent enough to make the semis.
good day/big win really? against who did he ever have a big win in his career in any slam?
not even roddick fans give him this kind of hype........his game is outdated in today's field and that is simply saying the truth........just because he is fedoriva's whipping boy, he has to get all the hype from fedoriva fans i guess........
Let's see, he dominated Djokovic in four (forcing him to retire) at the AO QF in 2009. He beat Murray in a solid match in the same year at a Wimbledon SF. He beat Ferrer last year in four at the USO.
Which brings me to my next point. Roddick did really well at the USO last year, beating Ferrer in the round of 16 when no one thought he'd be able to. Then he lost to some no-name *cough*Nadal, the eventual runner up*cough*. So yeah, don't count him out. Djokovic is really freakin' good, but he's been somewhat lethargic of late (didn't make it to the Wimbledon final, didn't even medal at the Olympics, got slammed by Fed in the Cincy final). Yeah, he won Toronto, but what decent player did he play? He beat Tomic, Querrey, Tipsarevic, and Gasquet, ALL of which are pretty inconsistent. And he beat Haas, who has been playing decent tennis as of late, but Djokovic dropped a set to him. So if Roddick flattens out his forehand and serves well, he'll beat Djokovic. Plus, Roddick has a winning record against Djoker

This goes against my prediction, but it is in no way idiotic to suggest that Roddick could make the semis. Though I WOULD like to point out, and I'm surprised no one else has, that Roddick's on the opposite side of the draw as Fed. They can't play in the semis as the OP suggested

Anyway, let's look at the draw. Roddick plays a qualifier first round. He'll most likely win that easily. Most likely Tomic is next, but he's inconsistent as all get out and has been on a very low streak recently, so Roddick will probably blow him away. Then it's probably Monaco. Monaco beat Roddick earlier in the year, but Roddick was coming off an emotional win over Fed, wasn't playing well, and Monaco was serving out of his mind. This could be a challenge, but Roddick will probably win it. Then it's Del Po. Here's his first real challenge. Del Po is an extremely tough opponent and has been on fire recently. HOWEVER, he has to go through Nalbandian (a has-been, but he's been playing well lately), most likely Harrison (always a good bet to give higher seeds a scare), and most likely Seppi, who has shown that he has a chance of upsetting big players. So Del Po will have a lot of early challenges that could give Roddick the edge. If Roddick utilizes his slice backhand to keep the ball low, Del Po should tire easily and Roddick could win this one as well. Then it's Djokovic in the round of 16. Look above for what I said about Roddick being able to beat Djokovic.
Then, finally, the quarters. It's difficult to determine who he'd face here. Supposedly Ferrer, but Ferrer's pretty weak on hard courts. My bet is Isner, and Roddick already beat Isner earlier this year, and can do it again. So yes, Roddick could very well make the semis. He hasn't played Tomic, is tied in the H2H with Monaco, has won the one meeting against Del Po since his wrist surgery, leads the H2H against Djokovic, leads the H2H with Isner, and beat Ferrer in a solid match at last year's USO. So all his possible opponents he stands a really good chance against. Is it likely that he'll reach the semis? No. Is it possible? Easily.