From Wikitravel

Every dimwit editor who sees himself as the source of all dreary blanc-mange plain porridge unleavened literature, licks his guillotine and eyes the neck of any author who dares to speak above a whisper or write above a nursery rhyme. -Ray Bradbury

The tone of Wikitravel articles should be conversational and informal. It should lie in a happy medium between all-out slang informality ("Yosemite National Park is DA BOMB!!!!") and constipated academic stuffiness ("Proceeding thence peripatetically on a compass bearing of north by northeast, thou shalt arrive within 20 imperial minutes at the mixological establishment yclept 'Hooters'.")

Lively writing is welcome. The requirement of being fair should not be taken to mean that all writing must be bland and encyclopedically neutral. For example, North Korea's human rights situation can and should be summed up as an "Orwellian nightmare", as opposed to noting that "some organizations have expressed concern about less than full compliance to international human rights standards, a charge vigorously denied by the Foreign Ministry."

Careful generalizations are OK, but don't cross the line into exaggeration. It's fair comment to say that "Switzerland will bust the average backpacker budget", but a little too much to say "Forget about visiting Switzerland unless you're willing to sell your kidneys".

See also: Wikitravel:Don't tout