Not a problem with the product itself, but with the RPGnow download. If you "purchase" this for free while you get the 4 page overview (which appears to be just a modified cover and the first 3 pages of the core rulebook of the full product) you don't actually get the 20 page "When Empires Fall" book.
The four (actualy 3) is fine in itself. It gives you an good overview of the setting, and if you are familiar with earlier version how it has changed. If you are interested in what the game mechanics are actually like though there is very little information.
If you can find When Empires Fall from another source (or they fix it here) this is actually a reprint of a two part article from Challenge Issue 64 and another latter one (may be issue 65 but not sure). This is a much more detailed background article but you will need to be familiar with the MegaTraveller setting to really follow this well as it explains in great detail the events immediately following that setting, which is in turn a set up for the New Era setting seventy years latter.