Comments on my previous entry expressed doubt about the correctness of the grammar of "I would like to thank ..." when it means "I am now thanking."
Don't worry -- it's fine. By way of explanation, I've hunted up highlights from an e-mail exchange I had in 2006 with Joe Pickett, the editor of the American Heritage Dictionary, in which I asked for his thoughts on a closely related point.
Here's a question I'm trying to answer:
Harold Shaw, of Penobscot, Maine, writes: "Tell them to stop it! When someone says, 'I want to thank all the little people who voted for me,' why don't they just go ahead and do it? Say 'I thank all the little' etc., and get it done with?"
Of course, "I want to thank ...," meaning "I am now thanking," is perfectly standard. (Similarly, "I want to tell you a story. Once upon a time ...") But I don't find a relevant definition in the AHD or any other dictionary. Doesn't seem to me that the ordinary "desire" meaning ("Used to express desire or intent: She said she would meet us at the corner") quite fits, because someone who says "I want to thank ..." is gratifying the desire. The "be in need of" meaning doesn't fit either. The idea is more nearly expressing an intention to ..., no? What am I missing?
I think this is related to polite requests using would and like and want, rendering what are really commands:
"Would you like to go to the store and get me some aspirin?" "Want to go to the store and get me some aspirin?"
I think it ostensibly fits the "desire" meaning but is used pragmatically to mean "please."
But let me look around a bit.
I looked in A Comprehensive Grammar of the English Language, by Randolph Quirk, Sidney Greenbaum, et al., and they confirm what I noted before.
As for would (I am simplifying):
p. 233 section 4.63 discusses "tentativeness or politeness: could, might, and would";
"Tentative Volition (in polite requests)" e.g. in "Would you lend me a dollar" would is more polite than will.
As for like (again simplifying):
p. 235 notes this: Hypothetical would when followed by a verb such as like, love, or prefer is used to indicate a tentative desire in polite requests, offers, or invitations: Would you like some tea? Thanks but I'd prefer coffee.
While this doesn't exactly address your reader's concern (the expression of thanks in public), the situations seem close enough. The expression of gratitude naturally calls for politeness and self-effacement, and so would like is the natural choice.
While we might not be taken aback if someone said "I thank all the people who made this movie possible," it's just not as polite as "I would like to thank . . ."