This UFO tease has been out on the web for a little over a year. Generally I shy away from Roswell discussions due to the muddied water effect that has accumulated over the past decade rendering any understanding of the case as a gross exercise in futility that leads to an unhealthy trip towards the realm of obsession.
Tony Bragalia has posted on Kevin Randle's blog, "A Different Prospective", an article stating that slides purported to be that of extraterrestrial aliens will be unveiled in Mexico City on May 5, 2015. The slides supposedly will show humanoid bodies that were recovered from a crashed UFO near Roswell back in 1947. The Roswell case is well known so I'll not go into any details.
Tony is of the opinion that the slides have a definite link to Roswell. He provides background as to how the slides surfaced...that in itself is interesting and raises some questions concerning authenticity. The slides are said to have been produced from vintage 1947 Kodak film...this has also raised numerous questions concerning authenticity.
As far as my take on this issue, I'll await the big unveiling later in May. I see no need to render an opinion based on something that I've not seen. That's not to mean that others have withheld their opinions and speculations as a quick look at the comment sections on Randle's blog and Rich Reynold's "UFO Conjectures" shows a varied range of such.
The only questions that I have is why Mexico City was chosen? What's the significance of this venue? Roswell is a slice of Americana folklore and it appears to be like everything else...out sourced to a foreign landscape.
Update: Reading my emails, Brit, Christopher Allan, pretty much nails it...the slides must definitively show that the photos were taken during the first week of July 1947, otherwise it proves nothing.
Reading the comment section of Kevin Randle's blog, it appears that the best that can be said of the slides is that they where imaged using 1947 Kodak stock. It is extremely doubtful that the slides will be pinpointed to a specific date in 1947. The theory being proffered by the slide proponents is that most people would have used up the film within weeks or months after purchase...I've seen no supporting statistics to bear this out.