Do playable "dyanamic" video results in internet search engine results fall within the fair use defense?
Here's a cursory legal glance at the issue, looking at things through the lens of the Kelly v. Arriba Software line of cases. The author thinks Bing video search results are less likely to qualify for fair use than traditional thumbnail image search results. I would tend to disagree; in my opinion, it's more difficult, given the size, to get much use out of the video search results, whereas a small image could still be useful in more situations. It's a more transformative use.
To my knowledge, the Perfect 10 v. Google case is actually the more relevant legal precedent potentially in play.
If you'd like to check out video search results in Bing, head here.