Mobile phone will never be able to fulfill ur gaming needs. Touch games just aren't as fun (talking about hardcore games not casual ones).
Still if you wanna game on ur phone, iPhone is the way to go. Tons of great fun games.
It is NOT a good idea to invest in any new PSP now. The new PSPVita will be released thi fall for $250. Save your money and prepare for that awesomeness. Ofc it won't be hackable for a while but trust me that is one powerful handheld console.
However, if you don't wanna wait... Get the PSP Slim n Lite (PSP-2000). I had it and it was pretty good and easily hackable. I'm not sure about the hacking of PSP-3000 but that's good too.
PSP GO is a no-go. Its expensive and not good enough.
dude just install a custom rom cm7 or fusionideos or dronix 0.4 and install their respective kernel, i forgot but one of these rom come originally with custom kernels like 729 mhz etc , CM7 is the best rom but with few bugs i have helped another friend installing it, fusionideos is good too am using it right now. add me @gmail if u wanna know more.
Yeah, a new non VR SP IP or a sequel would be best. They can't count to 3 so a sequel doesn't seem likely. Portal is my favourite and would love a sequel but don't expect one. I think I'll take whatever if they bring it on consoles too. Might go for VR as well.