If this happened, I may possibly never watch Smackdown again. Not because I wouldn't WANT to, but think about it: In Canada, ECW plays Friday at Midnight. It doesn't end until 1 am, therefore people watching ECW probably wouldn't get to sleep until at least 1:30 - 2am. Unless you're an ADHD attention-deprived 6 year old, there's no way you wouldn't wanna sleep in. People would miss Smackdown if they watched ECW the night before, and the ratings would plummet even further. This wouldn't be the wisest choice.
Also, I'm not as pumped to watch Wrestling in the morning. If I'm really tired, I'll tape ECW and watch it the next day. Not the next morning though, because wrestling just seems better in the evening.