“I'm sure it'll be nominated, but I'd be surprised if it won.”

You're talking with a friend of yours about a movie that you saw. She says that the movie is an Oscar contender. You don't think that it will win, so you say:

I'm sure it'll be nominated, but I'd be surprised if it won.

I'm sure (clause)

You actually say "I'm sure (something is true)" when you are not completely sure. You use it when you're guessing about something. The level of sureness is similar to "probably". But saying:

They probably won't mind.

sounds a little more careful, while:

I'm sure they won't mind.

sounds more confident.

When you use this phrase in writing, you should use "that":

I'm sure that it's perfectly safe.

it'll

This is short for "it will". You can say it this way in casual speech.

(something is) nominated (for an award)

To "be nominated" for an award means that someone has entered you into the competition for that award. For some kinds of awards, you can nominate yourself. For others, someone else has to nominate you. In the case of the Academy Awards, a group of film actors, directors, and producers choose who can compete for the award.

I'd be surprised if (something happened)

Use this phrase for talking about things that you don't think will happen:

I'd be surprised if we made more than a few dollars from selling it.

When you use this phrase to make a prediction, you sound pretty confident in your guess. But you don't sound very emotionally invested. In other words, it sounds like you don't really mind if your prediction turns out to be untrue.

We also have another phrase for talking about things that you think are possible:

I wouldn't be surprised if it won.

This just means "it could win".