According to Sony's CES (Consumer Electronics Show) website, they will be bringing Skype to the PSP. Under the PSP's feature set, Sony has listed:
Call friends, talk trash to fellow gamers or catch up with acquaintances via Skype for PSP system.
Skype on the PSP would be super hot, since it's an internet phone service that can make free internet to internet calls, or inexpensive internet to phone calls (and it's video enabled on PCs). With sexy enough integration into the PSP, it could sway people to make a call on the PSP rather than their cellphone when around Wi-Fi hotspots...if only the PSP handled Wi-Fi as well as a PC. CES kicks off next week and we'll surely have some more details on the venture then.