I agree that Thor's abilities will grow, though moreso because the story needs them to, unfortunately. I would love to see the movies show just how powerful Thor is -- to a reasonable degree at least. But they have to do it for the right reason: to strengthen the character in some way (i.e. make him more majestic). Sadly, the formula is usually to set up a villain powerful enough that the audience can believe the heroes might fail, and then write yourself out of it with an eleventh hour superpower, of which Thor is often the target (i.e. a god blast is a great aspect to Thor that directly references his heritage as a god/demi-god, but which used wrongly can be jarring). Simply put, Thor's powers leave a lot of room to pull some ability like that out of the aether
. Or hey, it could always be a conveniently placed deus ex machina (Tony finds that he can upload a computer virus to Ultron, and Independence Day and War of the Worlds references abound...ha!).
It's rare that the story will use actual teamwork, cooperation, and strategy to overcome a challenge, which is why the Avengers movie kind of worked. Well, except for the deus ex of Loki's spear I guess.
But I seriously hope that Thor doesn't resemble the Man of Steel in any way regarding decisions about overpowered abilities. The comics version of Thor could move at the speed of lightning if truly needed (although it was never really used during battles IIRC), which is thousands of times faster than the speed of sound. In real life, a lightning strike will rupture people's eardrums who are nearby, and lightning is composed of only electrons and plasma. A solid person moving at that speed, weighing around 100 kg, would kill anyone instantly at a fair distance away. Even though the Kryptonians probably only moved at a few times the speed of sound (just a guess I admit), I think that is why MOS showing what a "realistic battle between superheroes and villains would truly be like" was so silly in its claims. Everyone who could see Superman before he "blitzed" (or whatever they called it) would have been dead from the concussive shockwave hitting them a second later. No glass would have been left intact anywhere in Kansas. And I'm pretty sure a balloon would have popped at a child's birthday party somewhere.
First superhero lesson for DC: stop using that particular power unless you really enjoy killing all innocent bystanders, you psychos!