Do not all charms flyI think this notion is wrong. Science, when properly understood, doesn't destroy wonder, it enhances it.
At the mere touch of cold philosophy?
There was an awful rainbow once in heaven:
We know her woof, her texture; she is given
In the dull catalogue of common things.
Philosophy will clip an Angel's wings,
Conquer all mysteries by rule and line,
Empty the haunted air, and gnomèd mine—
Unweave a rainbow, as it erewhile made
The tender-person'd Lamia melt into a shade.
First, I'd like to clearly separate two relevant meanings of the word wonder. The first is synonymous with awe, the feeling you get when you think, "That's really really cool!". The second is synonymous with curiosity, the feeling you get when you think, "I wonder how that works...". They frequently come together, but they don't have to. It's entirely possible to feel awe at something that you understand completely, or to feel curious about something isn't particularly awe-inspiring.
Science enhances the feeling awe, because it reveals nature, and nature is, well, awesome. The real world is far cooler and more interesting than any fictional world I've ever read about (which is not to say that fictional worlds can't also be cool and interesting). I've written about this before, and given several examples of real awe-inspiring things. Most of those things would never be known about without science. And you can't have a feeling of awe towards something you don't know exists.
Science enhances curiosity in much the same way. Every question answered by science uncovers still more to be asked. Questions you wouldn't even be able to ask before, since you wouldn't have known the concepts they apply to.
I think the reason Keats, and others who make this claim do so because of two mistakes. First, they don't realize that the feeling of awe can be separated from the feeling of curiosity. Second, they don't realize that answering questions you're curious about can uncover deeper questions. If those two things weren't the case, then science would destroy wonder. Fortunately they're not.