Buffy creator Joss Whedon is known for consistently writing strong female roles. By his own account, he is consistently asked as to why he writes such strong females, to which he has famously responded, "Because you're still asking me that question." So with Whedon directing The Avengers, you had to figure Scarlett Johansson's Black Widow would be a prominent and formidable presence. Still, Marvel is paying Johansson for more than just her utter convincingness at portraying a lithe, Russian secret agent, so you also have to figure you'll be seeing her fleshy parts jiggle around a bit.
Assuming you have now figured both those things, the following clip should be just what you expect it to be. It's right in that sweet spot between "finally, a female with the confidence and chair-fighting aptitude of Jason Statham" and "oooh, a fetish film! I should masturbate!"