My paper did one, though as usual I wasn't told about it. Found out when I opened the front page this morning.
We've bantered around some ideas for an April Fool's story in sports the last few years but never actually did one. Probably because we think it's kind of juvenile as well.
<b>Now, me as devil's advocate:</b>
You might not think it's professional,but why is it so wrong to entertain? As long as you say at the end of the story that it's an April Fool's Day joke and make no bones about that fact, isn't it no different than running a humour column?
The only thing is that if you're running a fake story right beside one of an actual tragedy or anything else that would look equally bad on the same page, you might want to forget about the fun story that day and save it for a year when it's a slower news day.