PSP 2 will be launched very soon. A new model Nintendo DS will launch shortly after the PSP 2- say within a year. The consoles probably 2 years after the PSP and spread out over 2 years: 2013 and 2014 launches. 

Anyway is the PSP 2 the start of next generation or still part of generation 7?

Will the next XBox launch before both PS4 and Wii 2?  

Maybe Generation 8 will be a repeat of generation 7 as far as the new XBox having a year head start over Sony and Nintendo. Sony or Microsoft may beat out Nintendo in Generation 8 in the console sales wars. The order the consoles launch could be different: maybe Nintendo jumps both Microsoft and Sony and launches a year in front. 

Sony and Microsoft may actually launch at the same time or within a month. XBox 360 launching a year  in front of the PS3 and gaining developers support was a decisive factor in the HD console sales  battle between Microsoft and Sony.  

I think Phantasy Star Portable 2 already released.

The 3DS will be the first 8th gen platform

Portables never defined "Console" generations, they have their own Portable generations, but how do you know the PSP2 is going to release soon?

3DS then PSP 2 within a year. Then a year two later: Neo XBox, Neo Wii and PS4.

Where did you get that idea. 3DS launch within 6 months, PSP2 isn't even announced yet

Based on the OP, it was as if he had never heard of the 3DS. "New model Nintendo DS" lol.

Home Consoles define the start of a generation.

Not 3DS nor PSP2

and as it wan't announced during TGS probably won't be announced until E3 2011 at the soonest.

The DS started gen 7 and the 3DS will kick off gen 8.