No, he was able because he was “worthy” just as Thor couldn’t lift it again in the first movie until he proved “worthy” once again, and why Cap came the closest of all the Avengers other than Thor to lifting it, because he was almost worthy.
The last part was a nod to the comics when Cap was actually able to lift the hammer.
Also, while it wasn’t nearly as good as “Puny god!,” I really like Ultron’s offscreen, “Oh, for God’s sake!” right before Hulk disassembles him in the escaping Quinjet.
My fanwank is that Vision’s ability to wield Mjollnir is ultimately temporary. He’s a being with a fully developed moral code, who’s literally just minutes old. He hasn’t been alive long enough to have had to make the sort of moral compromises and difficult decisions that most adults have had to make by the time they’re in a position where they’re trying to lift a mystical Uru hammer. So, when Mjollnir does its worthiness check, it sees that Vision has exactly the right sort of moral code, and that he’s never once even come close to violating it. Therefore, worthy. But the longer Vision lives in the world, the more he finds himself in situations where there are no good answers, the more that worthiness chips away, until he’s just tarnished enough that he can’t lift Mjollnir again.
It may already have happened by the end of the movie, when he tracks down the last surviving Ultron-bot and destroys it - effectively killing what is, by that point, a helpless foe. Which is not to say that he made the wrong decision there - Ultron is clearly too dangerous to be allowed to live. But is Mjollnir interested in that sort of moral calculus? It seems to me that magical viking lightning hammers don’t really go for subtlety.
It could also be foreshadowing for Cap eventually being able to wield the hammer against Thanos in Avengers Infinity War.
I think the point they were going for is that Vision had just been created. He was an innocent that hadn’t had time to be corrupted by experience.
WHile the ‘vision’ had just been created - Jarvis was his core - and had been actively fighting the good fight against Ultron already.
He’s able to wield the hammer simply because he is (or was) worthy to wield it.
During the later battle - he was still able to wield it.
Did Tony Stark ever fix the tractor?
Looks like the theater web master just pulled the first thing he saw of an Image search.
The Vision was able to wield the Hammer so everyone, characters and Audience both, could be sure he was good. No tricks.
I missed my edit window…all this talk about Hawkeye and Black Widow I have seen here and elsewhere kind of surprises me. I never got any sense in the first Avengers that they were a couple. Just close colleagues and friends who had a history of working for SHIELD together. It never even occurred to me they might me romantic.
“Prima noctem”, huh? Stark’s lucky Lady Sif wasn’t in the room.
I dunno, later Thor makes the point that if he can lift the hammer, it’s safe to leave the infinity stone in his head. That’s a long term plan. Of course I’m not sure how they’d have gotten it out, if they’d wanted to, but that’s another movie.
There was no evidence of romantic interest between Black Widow and Captain America in Winter Soldier either. But it doesn’t matter. Some people see a available male character and an available female character and they start shipping.
Did Black Widow & Hawkeye ever have a thing in the comics? Can’t remember.
Vision having the mind stone will make him interesting to Scarlet Witch. I predict some shipping there. 
Untrue. In CA:WS she was wearing a necklace with an arrow. In an interview with Rotten Tomatoes during the CA:WS press junket, Scarlett Johansson said this:
Black Widow and Hawkeye do have a ‘thing’ in the comic books (as do Black Widow and Cap, and Black Widow and Bucky/Winter Soldier). So this wasn’t completely out of left field at all.
Spoiler for the comic books:
Vision and SW end up married in the comics. It wouldn’t surprise me if they follow through in movie canon… you can see stirrings of it on her face when he picks her up and carries her off toward the end of Age of Ultron.
I was teasing. I grew up with the comics. 
One of my favorite parts of the movie was the look on Thor’s face when Cap shifted the hammer.
But again… there’s nothing ROMANTIC about it. People talk about the arrow necklace like it’s this BIG part of the movie…seen the movie 3 times, maybe noticed it once?
People like to jump to conclusions because men and women aren’t allowed in media to be close without sex getting in the way. It’s like everything has to be When Harry Met Sally. The Hawkeye’s family bit was great because it played with people’s messed up assumptions in a real way–it wasn’t just “Hah! Fooled you!” It was “Yeah, they are really close. He has a wife and kids back home and Black Widow might as well be family too…enough to where they name a kid after her. What did you think was going on?”
I, for one, thought they were following canon. Particularly since the necklace showed up in CA:WS, where followers of the comics would wonder if the movie MCU would set the stage for Widow’s relationship with CA or Bucky. When they didn’t, and when Hawkeye was absent but Widow was clearly wearing a token that implied a strong outside-of-work relationship, it made sense to fall back on “Oh, they must be setting up Hawkeye-Widow instead.” I have had extremely close relationships with opposite-sex coworkers, and never wore something personal to show off our closeness. I can’t imagine many people have had that experience. Add in Johansson’s own comments, and it’s just not that far of a leap.
There is (AFAIR) no indication in the comics that Widow and Banner were ever a thing, which is why it was such a shock.
ETA: CA:WS came out a bit over a year ago. People who have followed similar logic to mine have had that long to get invested in a Hawkeye-Widow relationship. It’s understandable that they feel a little discombobulated.
You forgot Daredevil. Personally, I was waiting for a cameo appearance by Charlie Cox, or perhaps a mention of Nat’s blind lawyer boyfriend.
Okay, I wasn’t really. But wouldn’t that have thrown everybody for a loop? 
To be more serious, I was a little surprised that Natasha continued her romantic interest in Bruce despite his part in creating Ultron. Watching the film, that was my prediction for why their romance would go south. That she would be horrified/disappointed that he could be so careless and keep such a secret from the team, and it would kill her developing feelings for him. So points to the film for not going that route.