I am going to just say this...
You are vastly underhyping the expected crowds this Summer.
Just saying. We'll see who is right at the end of Summer.
Yeah, I dunno, I'm inclined to agree with you. The Transformers films had exceptionally strong international grosses, in addition to strong national box office results...
I guess I'm wondering, Tyler, where you're getting your info on South America and Europe. I don't have any info that contradicts what you're saying, but it's also not a commonly accepted fact that Transformers are *only* popular in America and Asia. South American tour groups are likely to come to Florida for the season anyway... if they see "big new thrill ride opened at Universal Studios," I think it's highly likely they'll make a stop there in addition to Disney or Sea World or wherever else.
As for traveling... keep in mind Transformers The Ride has only been open a couple of years in Cali. For a lot of people in the United States, at least, it takes a lot of planning and $$ to travel there (myself included), so many haven't had a chance to check the ride out in that state. Thus, everyone who might've been considering a pricey trip to Cali will now maybe instead travel to a closer, more inexpensive Orlando for their vacation since one of Hollywood's biggest draws is now here, too.
Harry Potter I think is a nonfactor for now. It was announced so recently and so suddenly that it'll have a minimal impact on vacations made this summer - they're already booked, and the locals who MIGHT've held off will come for Transformers. Holidays, yeah, I could see crowds being adversely affected. By how much, who can say, but a lot of vacations for that are probably booked already, too.
Merchandise-wise... I have no insight there and won't argue. I could see that being the case, as I personally don't see a lot of appeal in the merchandise on hand. (I'm also just not a big fan of the Transformers as a brand, though I enjoy the films as popcorn entertainment and am excited for the ride). I will say the Chocolate Allspark and Bumblebee Souvenir Cups are really cool, unique gifts. I expect Energon will be a big hit, too, when it's finally introduced.