GogetaSSJ4BR, iR Shell 2.0 already allows existing WiFi homebrew apps to use adhoc PC connectivity. For example, you can starts Links2 from iR Shell, iR Shell will then allow Links2 to use adhoc and connect to the PC without Access Point and browse Internet. To use this feature, you can refer to Adhoc WiFi PC Configuration section of the User Guide on the 1st post. Make sure the option "Allow Adhoc PC Connection for Homebrew" under iR Configurator is enable.
edit:even nethostfs isn't working

Have you personally tried links2? I'm trying to get it working with ver 1231, but it stucks in the step 3.
I 've followed instructions in the first post and I have the enable adhoc for hombrew activated, with a pc ip 10.0.0.1 and psp ip 10.0.0.2, it's in adhoc mode and I've shared the conection like I always do with my laptop, well, it is actually working with my laptop with no problems.
I have the default port 7513 opened in my firewall for the 10.0.0.2 ip and also the proper dns are setted up in the adhoc conection, named "Adhoc PC"
any ideas?
Also there is an issue with the pspmsx emulator (at least with 1.05 version).
I can't return to rishell and the home buton freezes's the psp, but the battery warning still appears, so irshell is still in memory.
I supose that is a problem of the emu