I think holidays should be left alone. They all have their roots in history (the big ones, anyways) and to mess with them is to destroy a part of the tradition and/or old ways that they uphold or provide. Personally, I am insulted that anyone would actually think of changing the name of any such holiday. The name is part of the history, and to change it is to give away what the holiday means and represents.
Halloween for instance is derived from All Hallows Eve, the day before All Hallows(mas), or All Saints Day, which was a time to honour saints and martyrs. This, in turn, started as what was known as Samhain, and still is, since the festivities of Samhain continued, albeit on a different day (November 2nd, known as All Souls Day). Every name of a holiday comes from the religion of which it was derived. To change the name, just because some people don't like it, a) doesn't help, because whatever the name, the festivities that take place are still the same (or should be), and, b) only takes away from the history of the festival, or holiday, as the derivation of the name change then has no historical background, with no link to the history of the festival/holiday itself. To want to call Halloween Octoberfest, is doing exactly that, because there is no historical link in the name Octoberfest.
History is important; it helps us know who we are, and where we come from.