Sometime in the last 7 to 10 years I spent a Saturday or Sunday at the B&O Museum after a business trip in the Philadelphia area. At first I was shocked at the admission price but soon found out I happened to be there on a Thomas the Tank weekend. It was a carnival atmosphere with lots of extra vendors and families present. The event itself was new to me though I vaguely knew about the Thomas character. Personally I found it was a distraction from the main exhibits and equipment at the museum. No doubt about it that it brought lots of people inside the museum! I have wondered since how many new visitors that day have returned to the museum on a non-Thomas Day and how many visitors--young and old-- have joined the museum or otherwise contribute to its long-term preservation efforts.
The skeptic in me says once the cutsey aspects of the Thomas fad fade with age the impact on the railroad hobby in this country will be negligible. [The UK is a different story perhaps.] Right now, it's a great cash cow so many sponsor it.
In the May issue of TRAINS there is supposed to be an article on the future of railroad museums and tourist railroads and the challenge of meeting the changing interests of the public. My instincts tell me there will be a great sorting-out of many museums, historical groups (like NRHS, R&LHS, and the RR-specific historical societies) and tourist operations in the next 10-15 years. Some will survive; some will thrive; and many will wither away. The trends are already present. The outcome will be the same with or without Thomas. Ditto for Polar Express.