Possibly, if they made a portable PS3 that came with a dock for play on TV I would buy it. But in fairness the main reason would be I already have quite a few PS3 games digitally owned on my PSN account.
But if it was a whole new console so none of the games I already own would work, and anything I want to play I would need to buy again - then no, I think it would go the way of the Vita.
Summary
If they did a handheld PS3 you use portable and on TV, and your back log of PS3 games worked with it (digital only ofc) I could see that doing well.
If it was a brand new portable console, I don't think it would fair any better than a Vita.
The best way to find out if you can trust somebody is to trust them.
Ernest Hemmingway