I don't know if you'll regret the trade-in but It's pretty obvious that impatient people like you are dream customers for game hardware companies. You already bought your 2nd PS3 and some day you'll probably buy your 2nd WiiU.
I bought my WiiU early and as a patient person with currently 6 different gaming platforms at my disposal I'd even wait 5 years for the first Zelda HD, plus: Nintendo decided to give us Wind Waker HD soon and Pikmin will also (most likely) be released this year.
So even though I'd never sell my WiiU (or any other system) there's nothing wrong about your decision. You can do whatever you want, but keep in mind: Buying systems twice doesn't save you money. If you kept your WiiU and your first PS3 you would have saved money and woulln't always think about the fact if one of those systems was not worth the money.
The more systems you have the more choices you have (and you won't spend more money on games, you'll end up buying the best/most interesting games of each system).
