It sure seems like there are a lot more frequent travellers afraid of bed bugs than there are bed bugs. If it were a HUGE problem, at least half of the flyertalk community would have tales of woe.
That said, it does seem to happen, so I assume reasonable precautions are appropriate. I don't put clothes or suitcases on beds, and I try to keep the suitcases zipped up and on a table at night.
My kids did get lice a couple years ago, and it was a pain in the neck to get rid of them (vegetable oil in their hair under a shower cap for several nights!). So I'd rather not deal with bed bugs. But unless you want to just stay home, I don't think there's much more to be done than just take reasonable precautions.