Obviously, I can’t answer the question from the title but even if it isn’t, it’s still an amazing song [dead now].
Here is Seth’s post on the topic. (Thanks!) [dead, see below] He says that “the song itself popped up in the comments section of the Nightly Roundup last night.” The crucial comment was posted by a certain Veronica: “http://youtu.be/GdvVWa4XYSs search this freshly leaked from my office pinkypie season2 song” (2011-11-06 14:09Z). As of now, they (or she) did not comment again on that post and the account seems to have been specifically created for the leak, as the profile page shows “On Blogger Since[:] November 2011.”
The YouTube video was uploaded by finkyfie “19 hours ago,” which put’s it at roughly (± 1 h) 2011-11-06 03:00Z. Interestingly, however, the account was created on 2011-10-13 already, but the earliest activity shown is from roughly 2011-11-06 14:00Z.
I’ll update this post if anything new comes to light.
Update 2011-11-06 22:23Z: I’ve downloaded the YouTube video using youtube-dl, and the modification time of the file is 2011-11-06 02-13-30Z.
Update 2011-11-06 23:03Z: A Google search for “Veronica said site:equestriadaily.com” returned exactly that one comment above, suggesting that they really only posted that one comment. (The search results may of course be different ones by the time you read this.)
Also many bronies seem to worry that somepony may get fired over this (“Veronica” seems to have been pretty cautious, though) or that the leak might be detrimental to our relationship to Hasbro. We can’t really influence the first worry, which seems unlikely, and the latter seems completely unfounded to me. How could this have any influence on the relationship between a corporation and the fanbase of a show they finance?
Perhaps it was even intentional. The pattern, however, seems very different: Usually such official “leaks” were fragmentary and occurred a day or two before the airing through the Facebook page or assorted media outlets. This one is complete, though low-quality, and was published in a very leaky way. Still, Daniel Ingram said on 2011-10-26: “Ok even I have to admit, it sure is taking a looong time for the first songs to appear this season... oh those fickle ponies! ;)” “Smile Pinkie” (which I assume is only a code name, hence the quotes) might be a simpler one of the upcoming songs and thus a good teaser that will keep the pony music buffs among us in good spirits.
Update 2011-11-06 23:20Z: Seth has deleted his original post, so take good care what you do with the information compiled here. If somepony working on the show were to ask me to remove the video link, I would certainly comply.
Update 2011-11-06 23:37Z: Given that Seth writes that “We were asked to remove it,” it’s pretty much confirmed to be legit. He wouldn’t remove it if the person asking him wasn’t in some way involved with the show. Also, “most of the rumors point to it being a Topdraw leak.”
Update 2011-11-06 23:51Z: @foalpapers points out that at the end of the video the name “Veronica Dela Cruz” is shown and that she is or was an animator for the show. Such a blunder, which on top of it all seems completely intentional, doesn’t fit the pattern of creating fresh accounts on Blogger and YouTube specifically for the leak. Besides, a professional animator ought to know better than to use Comic Sans.
Update 2011-11-07 00:31Z: I just feel like pointing out (and reiterating) that I do not support or condone the violation of trust that leaks might entail, unless they serve an overriding moral purpose. This is a decision you have to make. I don’t see any such purpose in this case.
Update 2011-11-07 01:44Z: Somepony named Wento suggested that it might even be a season 3 song “because season 2 should be compelete finished already, and that song seems to be fairly unedited.” He gives more reasons, which I find less convincing. Who knows.
Update 2011-11-08 09:22Z: The YouTube account seems to be gone now: “This channel is no longer available because the user closed their account.”
Update 2011-11-15 19:29Z: The messages by Amy on this page suggest that it is a season 2 song, since Amy says that she wrote the lyrics, but does not work on season 3. (Now that all the drama has cooled down a little, have a link to the PMV of the song that was up on YouTube five hours before Seth’s first post on the issue. Kudos.)
Update 2012-02-18 18:45Z: It finally aired!