It has nothing to do with "tampering" with the PS3, its all software related.

No you don't, if you read the article it tells you that you connect them through FTP servers, and you edit the PARAM.SFO file to enable Remote Play while being offline. It doesn't say anything about having an older firmware update, so as long as you don't sign in to PSN, even with the current firmware, it will still work.

you still need to be online...and there is no way of getting around a FW update when you try and connect to PSN

edit:

i see...i thought you had to be online for all of this to work while reading the article....bubbles for you...thanks for the info

Yay for hackers enabling a feature Sony abandonded. Seriously every PSN game should allow remoteplay unless it requires 2 analog sticks. PixelJunk is the only company I know that actually uses this great feature religiously!

so it is true...thanks for the vid

Quickly! Someone start a conspiracy of how Sony want you to buy to versions of the same game, one for PS3, other for PSP! /S

Just like custom soundtrack, the deature IS THERE. It's up to devs to use. Most ignore it simply because PS3 controller scheme isn't compatible to PSP controller scheme. There is ways to adapt to PSP controls and connectivity rightly, but again, most devs avoid the hassle. Also, as the PSP is limited to stream what PS3 is processing to it's scream (cloud gaming) and have to send the imput back, it's usually a laggy experience, so, again, not worthy it.

Obviously, some devs that put out really similar games on consoles and handhelds, also want you to buy both versions, but most games don't even spam versions to both PS3 and PSP, so most wouldn't even be able to profit from it.

ON TOPIC:
I love how this hackers only cared to develop backup manager (a piracy app) to start selling USB Jailbreaks, but when they got blocked they all of a sudden want to show people how many marvellous things they could of have done with PS3 homebrew, with features Sony supposedly locked... PS2 BC, PSP full remote play, etc...

It's always the same shit, when GeoHot was about to hack PS3 through OtherOS, everyone just talked about getting free games, how GeoHot could install custom FW modified from original PS3 FW that avoided security measures... But when Sony took alway the OtherOS feature people complained that it could have raised a homebrew scene (despite the fact that OtherOS was already a homebrew enabled platform for PS3 hardware, like if you install any linux PPC distro and develop apps to run on PS3, you could even develop your own PPC OS).

This kids should man up and cut the lame excuses, all the smartpants care about is free games. They never wanted homebrew (OtherOS was completelly ignored by homebrew community), PS2 BC (they already have a PS2 with a modchip and a bucket full of pirated games) nor PSP full remote play (cause after PSP, SNES, NES, Genesis and PS1roms that was the one thing they couldn't piratemulate on Pandora'ed PSPs - streamed pirated PS3 games).

So fix the five games. I doubt that's the reason though.

I would assume its because of the lack of second analog stick on the psp.
Or maybe as bishop-br pointed out, they want to sell you the same game twice. I wouldn't classify it as a conspiracy theory if you have some idea of the mentality behind corporations.

because it's up to the developers and the developers are not willing to put the time in and patch it.

That and the 2nd analog stick problem.

Most games don't work as it is...How would enabling all but "5" make things worse?

For sure. I don't even think it would need that talented of a studio. Upping the resolution and framerate would be all that's needed. Of course I would take the trilogy with a complete overhaul on the graphics, but upping the rez and framerate (and some great AA) would easily be enough for me.