Well now, Intomobile has an interesting article which claims the next iPod Touch will feature some of the iPhone’s goodness such as a camera and a microphone and is due in the next 3 months.
This will then turn the MP3 player into a respectable VoIP handset without the need for a VoIP application such as Skype when used in conjunction with a mic.
So maybe having a microphone built in along with virtually identical software the iPhone uses may just get more people to use these services and the iPod Touch. That is of course if this is true, so lets wait an hear from Apple first.