I dont know about phone models...haha
I bought one walkman phone since 2005, still use until now.
maybe next year will get OMAP4 phones...hd+3d+touchless interface 

maria ozawa gone
hehe...but her videos remains forever...

btw...forgot to add

psp2 with phone functionality is wishful thinking,

Sony wont merge phone with psp, not because they cant, but the dont want to.
Just stop and think, phone market easily is one of the fastest growing tech, with short life cycle.
and sony already got sony ericsson division.

if they merge phone into psp2, sure they can take some market away from phone market,
to those who want big lcd phone with great gaming capabilities
theyd surely profit big time at the beginning

but thats short term only.

long term, they'd lose profit, as gaming dont share the same short life cycle as phone does.
they need time to be developed.

theres ppl who buy phones on yearly basis, sell old one, buy new one which just come out
but for handheld, the case is not the same.ppl hold on to their gaming devices.

hence, if ppl already got phone, they wont buy any more phones,
cos they already have phone AND mobile gaming device already.

if sony dont have phone division, sure already exist psphone.but sadly, sony already have sony ericsson.
TL,DR:psp2 also wont be a phone.EVER.FOREVER.AND EVER.