Dictionary.app

It appears that the dictionary used in applications (within text fields, etc.) for spell checking is not the same as the "dictionary" used by Dictionary(.app). The word "preemptively" is flagged as being incorrect, the suggestion is "pre-emptively". However, a quick search in Dictionary shows:

preemptive
adjective
serving or intended to preempt or forestall something, esp. to prevent attack by disabling the enemy : preemptive action | a preemptive strike.
• relating to the purchase of goods or shares by one person or party before the opportunity is offered to others : preemptive rights.
• Bridge denoting a bid, typically an opening bid, intended to be so high that it prevents or interferes with effective bidding by the opponents.
USAGE See usage at peremptory.

(I like the example of a preemptive strike, quite topical considering the news coming out of the US on Iraq.)

Also, the Command-Control-D shortcut for invoking Dictionary doesn't like hyphenated words. And another thing, double clicking on a word in the full dictionary (i.e. the app not the popup) takes you to the entry for that word, very nice. Seems like it's using WebCore for the rendering, a copy and paste to get the definition above gave me some words in lowercase, even though they're in uppercase in Dictionary, my guess is CSS to the rescue.