It'd probably be a mistake to brand the ngp with the PS3. The PS3 is almost 5 years old, and regardless of how long they'd like to have this system relevant, Sony will have to keep up with the competitors when they release their next generation consoles.
So, conservatively, I'd say the PS4 comes out in 2014.
If the NGP is named to be linked with the PS3, it becomes outdated in only 3 years. That's half of the PSP's lifecycle (The PSP is nearing its 6 year anniversary in America).
So, while it would be great to play PS3 games on this system, it needs to be named something to establish it as a step beyond the PS3... a handheld system that's technically halfway between this generation and next.

I understand why they would dump the psp name... to avoid the confusion between a Playstation Portable and a Playstation Phone. Sony will likely have some over-simplified name for it, like the Move. Hopefully not "The Handy".

Quote: I think everyone will agree that the NGP(psp2) is just a code name and not the actual name of the unit.

dude we thought the same thing about the DS and it turned out we were wrong. We thought the same thing about Natal and it turned out we wished we were wrong. NGP is a stupid name. Almost as stupid as Wii and definitely more stupid than Kinect.

Will they stick with NGP... that's a tough call. I say no. Will they go back to PSP2 it could happen but I'll put money on No. Sony wants to run away from the PSP name as fast as they can. That name is poison. They'll probably go with Playstation *Verb* or something hip-sounding.

PS3-Portable? nope. way too long complex and the numbering scheme doesn't make sense. They wouldn't name a phone like that and phone naming conventions don't exist they make it up every time they release one.