Seth obviously makes a good point of why grand openings are often superfluous and missing the intended point of the party throwers, very often, at least. I have one example of the contrary.
One year and a half ago, my school changed its name, something I commented on, although I in Danish. The day of the name change, my school threw a huge party for all high school kids in Copenhagen, a so-called “grand opening”. And it really was. I personally found the party to be dreadful, because the school was crammed, and the queue to the bar was endless.
But the outcome was all as desirable as one could have hoped for, maybe even more so. The school has for the past many years had a quite bad reputation, and thus no-one wanted to go here. However, this school year (that is, starting August 2007), we almost had all our places filled with people who actually applied for the school.
No-one can be sure that this was because of the party, but I believe the heavy branding of the school was a key factor. Thus, a grand opening might just be what is needed. Or it may not, as many of Seth’s examples show.