Yahoo just announced the other day that an official messenger app with video for Android is coming out soon, so watch out for that.
Plus Skype is going to release a Galaxy S compatible version of Skype soon as well (other Android phones work with Skype right now). :(
So for now, it's only phone to phone (via Tango, not my favourite but it works) for us Epic users. I just completed a Tango test call from my Epic to a friend's iPhone 4.
Forgive My Brevity. To Be Or Not To Be...
Epic Touch (Galaxy)
Nexus S 4G
Epic 4G Touch (Galaxy S2)
Galaxy Note 2 (Current)